look up any word, like ratchet:
 
5.
A holiday self established by marijuana smokers that takes place on April 20th.

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: My dad got so baked yesterday.
You: Why?
Me: It was 4/20.
by dotVillain April 21, 2009
 
15.
The word 4/20 comes from a couple of things firstly, a young man (greek) by the names kosta h(btw i hear his hot) or so not sure about his full name invented it by smoking tons of weed euuurddaaay at the same time he noticed a pattern in this. Everyday it would be at 4:20 after school... so from there he new he had to start calling it that. Secondly 4/20 is also a cops way of reporting that ppl are smoking weeed. thirdly, an event in amsterdam (weed capital) at the 4th month of the 20th day of the 4th hour of the 20th minute evryone in amsterdam would smoke the mary-jane.
"hey common lets go 4/20 (ppl dont noe wat it is so lets call it that and wont get caught XD)"
" we have a 4/20 in progress at jane and finch"
by "DA BOSS" April 21, 2009
 
16.
when all the the lil' kiddies get high and jus all around fucked up. A religious holiday considering it falls on a sunday and passover weekend.
Mom- Honey, I just realized its 4/20 and I let our son, Jimmy go over Bob's house all day. wow, i know what they are doing...
Dad- Shit!
by ily4 April 15, 2008
 
17.
some say it was bob marlys birth day (rong). others say it was when a group of college students (aka the "waldos")gathered every day at 4:20 to smoke pot. anuther theory is that 4/20 was the date weed became illegal, or it was hitlers birth/death day
"hey man comin over for 4/20"
by the sceptic August 19, 2008
 
18.
1. Smoke up ya fucking pot-heads
2. the birthday of the fucked up man that we all no and hate as Adolf Hitler
pot-head #1: hey man...its 4/20 u no wat that means dont u
pot-head #2: yeah dude...i have the weed
by ;alkfdyu;c;ebek May 03, 2007
 
19.
Day of the Columbine High School tradgedy.

"hey isnt 4/20 weed smoking day?"
"no you ass its the day the columbine shootings happened"
by pppppeeeace April 26, 2006
 
20.
2/10. or more properly 1/5.
"the answer is 4/20"
"dont you mean 1/5? idiot."
by glencorathecat April 20, 2005