look up any word, like cleveland steamer:
 
1.
Just generally trippin', tweakin', weird, actin' a fool, blackin' out, goin' off. Not necessarily due to drugs, though that's the obvious reference.
Homie was on one, just buggin' like I shot his mom or something.
by Kuahmel January 22, 2009
 
2.
To be fucked up on whatever your drug of choice is. It is beyond just tipsy or lightheaded, it's full on faded/twisted/tweaked/trippin/high/etc.
Damn, Rick James was on one back in the 80's.

That bum jackin off in the corner must be on one, damn tweak.
by Joe Blaze January 25, 2008
 
3.
to be under the influence of methamphetamines
i heard joe's been on one for the past three days
by Leya Fish January 19, 2003
 
4.
To be under the influence of methamphetamines AKA ice,meth,speed,dope,etc.
Tuttie's on one man, he been smokin' ice all week!
by rooster760 February 28, 2005
 
5.
Mass consumption of alcohol/drugs. Going past the point of no return and coming back only to return again.
You might have been one one if:
Its 9am and you are lying naked in bed next to a 300 lb. Miami, who you have never met before, with a peculiar taste in your mouth.
You wake up in the drunk tank and you have been told you’re being booked for defecting on top of car in a shopping center parking lot in broad day light.
Kid 1 "I have never seen that kid sober"
Kid 2 "He is ALWAYS on one"
by oneder April 30, 2005
 
6.
to be high, faded, to have just smoked weed.
My man James was on one at the party.
by metalgearray February 20, 2005
 
7.
To be sexually stimulated.

When the pussy/dick gets hard when thinking nasty thoughts and it needs to be touched.
I'm on one now just thinking about sex lol.

If I talk dirty to you then trust, you will be on one.
by Kietee025 June 25, 2006