four-twenty
noun
1
marijuana. Also written as '4:20'. False etymologies abound; the term was coined by teenagers in Marin County, California, and does not refer to any police code US, 1969.
2
any time that is considered the appropriate time to smoke marijuana. Also written as '4:20'. Coinage is credited to California students in the 1970s then, via the scene surrounding the Grateful Dead into wider usage US, 2004