Weed Slang Explained: 420, Cross-Faded, Za and What the Words Actually Mean

Cannabis has more slang than any other legal product in Canada, and most of it exists because the product was illegal for ninety-five years. Coded language was a safety feature. Legalisation removed the reason for the code but not the vocabulary, so the words stayed and the meanings drifted.

Most stoner slang lists on the internet copy each other and get the biggest term in the category wrong. This guide defines the words people actually search for, and checks the four claims in this topic that can be checked against something other than another slang list: where 420 came from, whether 4/20 is dangerous on the roads, what happens when you mix cannabis and alcohol, and why the munchies happen.

The Weed Slang Glossary

Most cannabis slang falls into four buckets: words for the plant, words for quality, words for what it does to you, and words for the ritual. Knowing which bucket a term sits in tells you most of what you need about how to use it.

Words for the plant and the product

Words for effects and states

Words for the ritual

Not covered here: quantity slang. Zip, eighth, QP, dime and the rest are weights-and-buying vocabulary rather than culture vocabulary, and they belong in a guide built around measurements. This one stays on words for the plant, the quality, the effects and the ritual.

What Does 420 Mean?

420 means cannabis — as a time, a date, a code word and a filter on a rental listing. The 420 meaning people search for is usually the first one.

The best-documented origin is a group of San Rafael, California high-school students in 1971 who called themselves the Waldos and met at 4:20 pm to search for an abandoned crop.^[1]

The hunt failed. The number stuck, first as their private shorthand for a plan to get high, then as a general one. It spread through the group’s connections to the Grateful Dead’s touring circle, and by 1990 High Times had picked it up from a concert flyer and started printing it.^[1]

Why is 420 weed day?

April 20 became the date because the time became the code. Once 420 meant “time to get high,” a calendar date reading 4/20 was the obvious annual version, and the first organised gatherings grew from the same Northern California scene the term came out of.

Worth being straight about the evidence: this account rests on the Waldos’ own archive of postmarked letters and artefacts rather than on independent scholarship. It is the only origin story with any documentation behind it at all, which is why it is the accepted one — not because it was proven in a lab.

Is 420 a Police Code?

No. California Penal Code section 420 is a misdemeanour offence about unlawfully preventing someone from entering or settling on public land.^[2] It has nothing to do with cannabis, and it is a police radio code in no jurisdiction anyone has produced.

This is the most repeated wrong answer in the topic, and it is also the easiest one to check — the statute is a paragraph of public text. Every other popular origin fails just as quickly.

Is It More Dangerous to Drive on 4/20?

Probably not measurably, though the headline said otherwise. This is the most interesting fight in the topic, and it is a good demonstration of why a single striking study is not the end of a question.

In 2018, a research letter in JAMA Internal Medicine analysed 25 years of US crash data and reported a 12% relative increase in fatal traffic crash risk after 4:20 pm on April 20, compared with the same hours one week before and after — around 142 additional deaths across the whole period, with the largest effect among drivers under 21.^[3] It was covered everywhere.

A reanalysis published the following year in Injury Prevention took the same data and widened the comparison — control days two weeks either side, then April 20 against every other day of the year. The effect largely disappeared. The authors found little evidence of a reliable 4/20 excess, and noted that genuine holiday effects such as Thanksgiving and July 4 show up consistently year after year in a way 4/20 does not.^[4]

The reanalysis author’s own framing was that this is not a debunking so much as the process working: an eye-catching estimate got scrutinised and turned out not to be robust to reasonable changes in the comparison group.

Do not read that as “driving on 4/20 is fine.” Two separate claims are in play. Whether April 20 specifically produces a crash spike is unresolved and looks unlikely. Whether driving impaired raises crash risk is not in dispute, and Canadian lower-risk use guidelines recommend not driving for at least six hours after use, and specifically advise against combining cannabis with alcohol before driving, because the impairment compounds.^[6]

What Does “420 Friendly” Mean?

It means cannabis use is tolerated in that place or by that person. You will see it on rental and roommate listings, short-term stays, event pages and dating profiles. It is a social signal, not a legal status.

The distinction matters in Canada, because a landlord, a hotel or a strata can prohibit smoking on a property that sits in a province where consumption is otherwise legal. “420 friendly” tells you the person you are dealing with is relaxed about it. It does not tell you the building’s rules, the municipality’s public-consumption bylaw, or your lease.

What Does 710 Mean?

710 is 420 for concentrates. Written down and turned upside down, 710 reads as “OIL” — which is how the number got attached to dabs, oils and extracts, and how July 10 became the concentrate counterpart to April 20.

It is a much younger term than 420, tied to the growth of the extract market rather than to prohibition-era code. You will see it on packaging and event names. If someone says “710 culture,” they mean rosin, live resin, shatter and hash rather than flower.

What Does Cross-Faded Mean?

Cross-faded — also written crossfaded — means being drunk and high at the same time — usually in the specific sense of having overshot, because the combination lands harder than either substance does alone. Unlike most slang in this article, that folk observation has controlled data behind it.

In a study of 19 participants using a vaporizer, adding a low dose of alcohol (targeting roughly 0.065% breath alcohol) raised median peak blood THC from 32.7 to 35.3 µg/L at the low cannabis dose and from 42.2 to 67.5 µg/L at the higher one. The authors noted the higher THC concentrations may explain the increased performance impairment seen with cannabis-alcohol combinations.^[5]

Two things follow, and only two. The same amount of cannabis puts more THC in your blood when there is alcohol on board, and the impairment from the pair is worse than from either alone — which is why Canadian lower-risk guidelines single out the combination before driving.^[6]

What Does Za Mean?

Za — also written zaza — means high-grade cannabis. It is one of the newer terms in circulation, carried by hip-hop and short-form video rather than by any regional tradition, and it functions as a claim about quality rather than a description of a product.

The commonly repeated etymology is that it is a clipping of “exotic,” reduplicated into “zaza.” We could not find any authoritative source for that, so treat it as a plausible story rather than an established one. Nobody has documented where this word came from.

What is worth knowing is what it is doing. Za is a status word. It signals expensive, scarce, imported or hyped, and it makes no verifiable claim about the flower in front of you — no cultivar, no test result, no grade.

Loud, Gas, Mids, Reggie and Dank

These are the quality words, and every one of them is a sensory judgement rather than a specification. They describe how a flower smells and looks to the person using the word — nothing more, and none of them appear on a certificate of analysis.

Two of these carry information. Gas names an actual aroma family, and dank tends to track cure quality, which is something you can verify by touch and smell. Loud, za and exotic are volume knobs on the same claim.

Canadian sites usually sell against a letter grade — AA through AAAA and Craft — which is at least a consistent scale within one store. It is still a seller’s judgement, not a lab measurement, and it does not transfer between stores. Treat both systems as aroma-and-appearance shorthand.

Naming the tension, since we sell this stuff: we grade our flower AA to Craft, and that grade is our opinion of how it looks, smells and cures. It is not a THC ranking and it is not a promise about how it will feel. Anyone selling you “za” is making a smaller claim than they sound like they are.

Why Are They Called the Munchies?

Because appetite increase after cannabis is reliable enough to have earned its own noun. The mechanism was identified in 2015 and it is genuinely strange: the brain cells responsible for telling you to stop eating get switched into telling you to keep going.

Hypothalamic POMC neurons normally promote satiety. Researchers found that activating the CB1 cannabinoid receptor increased POMC neuron activity while selectively increasing release of β-endorphin — an opioid peptide that drives feeding — rather than the appetite-suppressing peptide those same cells usually release. Blocking opioid receptors with naloxone blocked the cannabinoid-driven feeding entirely.^[7]

The work was done in mice, which is the standard caveat for this kind of neuroscience. It does not tell you how much anyone will eat, or which foods. It does explain why the effect is consistent enough across people to have become a word.

Is Couch Lock Real?

The experience is real. The usual explanation for it is not. Feeling heavy and immobile after a strong dose is common and well described. The story that it is caused by indica genetics, or by the terpene myrcene, does not survive contact with the data.

A genetic study of labelled samples found no clustering by “indica” or “sativa” label, with myrcene the strongest single predictor of an indica label — and even that explained only about a fifth of the variation.^[8] A separate analysis of roughly 90,000 commercial samples found labels did not align with chemistry at all.^[9]

The honest version is unsatisfying: dose, tolerance, setting, sleep debt and what else you have taken explain more than the label does. Our guide to sativa, indica and hybrid goes through the evidence in full, including why “just follow the terpenes instead” is also weaker than it sounds.

What Does Greening Out Mean?

Greening out means taking more than you can handle and feeling acutely unwell for it — usually pallor, nausea, dizziness, sweating and a sharp spike of anxiety. The name comes from the colour people go. It is unpleasant, common with edibles, and self-limiting.

The pattern is nearly always the same: a dose taken faster than the effects arrive. Edibles are the classic case because onset is slow, so a second helping goes in before the first is felt. Alcohol on board makes it more likely, for the reasons in the cross-faded section above.

There is no useful trick to speed it up. Sit down somewhere cool, drink water, do not drive, and wait it out. If symptoms are severe or someone cannot be roused, that is a call to a health line or emergency services rather than something to ride out — the point of the word is that it describes a bad time, not a diagnosis.

What Is Hotboxing?

Hotboxing is filling a small enclosed space — a car, a bathroom, a tent — with cannabis smoke. The idea is that nothing gets wasted. The trade-off is that everyone present is breathing the smoke that came off the lit end, not just what came through the joint.

That distinction is not trivial. Health Canada researchers comparing cannabis and tobacco smoke found that sidestream cannabis smoke — the plume rising from the burning tip between puffs — carried higher polycyclic aromatic hydrocarbon levels than tobacco sidestream, even though mainstream cannabis smoke ran lower than tobacco on the same measure.^[10]

So hotboxing concentrates the fraction of the smoke that is least worth concentrating. Ventilation is the entire fix, and it costs you nothing but a window.

Pot, Grass, Herb and Mary Jane

The older words are mostly euphemisms built to be sayable in public. They come from a period when naming the thing directly carried a legal cost, which is why so many of them are agricultural, domestic or floral rather than descriptive.

Notice how many entries in the third column are hedged. Slang etymology is mostly oral history, and the confident single-sentence origin you see repeated across word lists is usually one person’s guess that got copied.

Why Is It Called Marijuana?

The word came into English from Mexican Spanish in the early twentieth century. Beyond that, the tidy story most articles tell — that US officials deliberately adopted a foreign-sounding word to racialise the plant — is more contested among historians than the internet suggests.

The familiar account runs like this: cannabis was known in English-language medicine as cannabis; anti-drug officials, Harry Anslinger prominent among them, pushed “marihuana” to tie it to Mexican immigrants; the racialised framing then carried prohibition. Anslinger’s own rhetoric was documented and was explicitly racist, which is why the story is persuasive.

The complication is the wider framework it sits inside. A historian of Mexican drug policy has argued that the “Mexican hypothesis” — that Mexican migrants introduced cannabis use to the US and that prohibition followed as a tool against them — rests on much weaker source evidence than its dominance in the literature implies, and that cannabis was in fact uncommon in Mexican immigrant communities of the period.^[11]

Both things can be true: the enforcement rhetoric was racist, and the specific causal story about the word is not settled history. Today the practical answer is simpler — many in the industry prefer “cannabis” precisely because of the term’s association with that era, and both words are in ordinary use.

Why Weed Slang Ages So Fast

Cannabis vocabulary ages in waves, and the fastest-dating words are the ones that encode illegality. This is our own read rather than a sourced finding, but it predicts which terms sound dated better than anything else we have found.

Sort the vocabulary by what job the word was doing when it was coined and a pattern falls out. Words invented to hide something stop working when there is nothing to hide.

The test for whether a term will last: does it name a distinction you could point at? “Cart” names a specific object. “Terps” names measurable compounds. “Za” names nothing you can inspect, which is why it will be replaced by another status word within a few years, exactly as “fire” and “loud” were.

The corollary is useful when reading listings. Product-era vocabulary tends to mean the seller is describing something. Status-era vocabulary tends to mean the seller is claiming something.

Canadian Slang and What a Store Can Legally Say

Canadian cannabis slang is largely North American, with a few local habits — “greenery” and “dep weed” turn up regionally, and the letter-grade system (AA to AAAA and Craft) is a distinctly Canadian retail invention rather than a slang term at all.

The more useful thing to know is why licensed marketing sounds so flat. The Cannabis Act restricts promotion sharply, including promotion that could be appealing to young persons, and prohibits creating a false impression about a product’s characteristics, effects or health impacts.^[12]

That is a large part of why regulated packaging says “dried flower, 3.5 g, 22% THC” and never “loud.” Slang that makes an effect claim is exactly the kind of promotion the rules target, which is one reason the vocabulary lives in the culture rather than on the label.

Frequently Asked Questions

References

1. Snopes. The Origins of 420. Fact-check of the competing origin claims, including the Waldos account and the penal-code, police-code and Grateful Dead room-number claims. snopes.com/fact-check/420 (A fact-check of an oral history, not a peer-reviewed source — cited as such.)
2. State of California. Penal Code section 420 — misdemeanour offence for unlawfully preventing, hindering or obstructing any person from peaceably entering upon or establishing a settlement or residence on public land. Full text
3. Staples, J. A., & Redelmeier, D. A. The April 20 Cannabis Celebration and Fatal Traffic Crashes in the United States. JAMA Internal Medicine, 2018, 178(4), 569–572. DOI: 10.1001/jamainternmed.2017.8298
4. Harper, S., & Palayew, A. The annual cannabis holiday and fatal traffic crashes. Injury Prevention, 2019. PMID: 30696698 (Volume and page numbers not confirmed at time of writing and deliberately not stated.)
5. Hartman, R. L., Brown, T. L., Milavetz, G., Spurgin, A., Gorelick, D. A., Gaffney, G., & Huestis, M. A. Controlled Cannabis Vaporizer Administration: Blood and Plasma Cannabinoids with and without Alcohol. Clinical Chemistry, 2015, 61(6), 850–869. DOI: 10.1373/clinchem.2015.238287
6. Fischer, B., Russell, C., Sabioni, P., van den Brink, W., Le Foll, B., Hall, W., Rehm, J., & Room, R. Lower-Risk Cannabis Use Guidelines: A Comprehensive Update of Evidence and Recommendations. American Journal of Public Health, 2017, 107(8), e1–e12. DOI: 10.2105/AJPH.2017.303818
7. Koch, M., Varela, L., Kim, J. G., Kim, J. D., Hernández-Nuño, F., Simonds, S. E., et al. Hypothalamic POMC neurons promote cannabinoid-induced feeding. Nature, 2015, 519, 45–50. DOI: 10.1038/nature14260
8. Watts, S., McElroy, M., Migicovsky, Z., Maassen, H., van Velzen, R., & Myles, S. Cannabis labelling is associated with genetic variation in terpene synthase genes. Nature Plants, 2021, 7(10), 1330–1334. DOI: 10.1038/s41477-021-01003-y
9. Smith, C. J., Vergara, D., Keegan, B., & Jikomes, N. The phytochemical diversity of commercial Cannabis in the United States. PLOS ONE, 2022, 17(5), e0267498. DOI: 10.1371/journal.pone.0267498
10. Moir, D., Rickert, W. S., Levasseur, G., Larose, Y., Maertens, R., White, P., & Desjardins, S. A comparison of mainstream and sidestream marijuana and tobacco cigarette smoke produced under two machine smoking conditions. Chemical Research in Toxicology, 2008, 21(2), 494–502. DOI: 10.1021/tx700275p
11. Campos, I. Mexicans and the Origins of Marijuana Prohibition in the United States: A Reassessment. The Social History of Alcohol and Drugs, 2018, 32. DOI: 10.1086/SHAD3201006
12. Government of Canada. Cannabis Act (S.C. 2018, c. 16), ss. 17–18 on promotion, including promotion appealing to young persons and promotion creating a false impression about characteristics, effects or health risks. laws-lois.justice.gc.ca

This article is for informational and harm-reduction purposes only and is not medical advice. Do not drive after using cannabis, and do not combine cannabis with alcohol before driving. Follow the cannabis laws applicable in your jurisdiction.