420

American  

[fawr-twen-tee, fohr‐] / ˈfɔrˈtwɛn ti, ˈfoʊr‐ /

Or 4:20 or 4/20

noun

Slang

1. marijuana.

   Are you carrying any 420 on you?

2. marijuana drug use: The guys at the party were all 420-friendly.

   Police presence at the concert discouraged 420.

   The guys at the party were all 420-friendly.

3. the twentieth day of the fourth month, or the time 4:20, when referenced as a day or time for cannabis consumption or the celebration of marijuana culture.

   The head shop has a big pipe sale every year on 420.

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Usage

What is 420? 420 is a slang term (or a kind of code word) referring to marijuana or marijuana use. Due to this association, 420 is also used as the name of an unofficial holiday that marijuana enthusiasts celebrate by using marijuana. It is sometimes called Weed Day (weed is a slang term for marijuana).

Etymology

Origin of 420

First recorded in 1970–75; a code word derived from the meeting time of a particular group of marijuana smokers in 1971, later popularized by fans of the band the Grateful Dead

Example Sentences

See Examples For:

420

Together, these 420 chemical reactions form the metabolic network known as metabolism.

From Science Daily ● Aug. 12, 2026

Men can get breast cancer too, with about 420 new cases every year in the UK.

From BBC ● Aug. 4, 2026

My purpose is to put a name to the joy I felt last week, testing the Lotus Emira 420 Sport at the company’s test track in the East Anglia region of England.

From The Wall Street Journal ● Jul. 25, 2026

That sale includes 420 Atacams—missiles that put China’s southeastern coast within range.

From The Wall Street Journal ● Jun. 10, 2026

Each one stood 420 feet tall, the equivalent of a thirty-story skyscraper, and had three whirring blades.

From "Killers of the Flower Moon" by David Grann