So named because it is 420 centimetres long.
420 (plural 420s)
Unknown, although numerous theories abound; see Wikipedia; the most commonly-cited theory is that it originates from the time (4:20 pm) one particular group of smokers, the Waldos in San Francisco, met.
- (slang, especially Canada, US) A phrase used to identify oneself with the consumption of cannabis, or cannabis culture. (Can we add an example for this sense?)
- ^ Oxford Dictionaries, "We added 420 to the OED. Here’s how it happened.", 20 April 2017
- ^ Oxford Living Dictionaries, "420"