Originally started by a group of college kids who would meet at a statue everyday at 4:20 PM to smoke weed.
Some other drug usage may take place but marijuana is the main one.
Pronounced "four twenty", if you say, "four hundred twenty" you'll look like an idiot.
Me: It was 4/20.
"happy holidays, its 4/20"
4:20 was the time of day some stoners at San Rafael High in Northern California (represent) would get together every day after school to smoke weed and get high. It is now a huge part of our culture, basically the word for the "weed culture."
It's also a holiday, April 20th, (coming up!) and the only place to be at 4:20 on 4/20 is Hippie Hill in San Francisco.
shit, what are you doing on 4/20? GETTING HIGH OF COURSE