A term used to describe the high of heroin.. it is often mistaken as being very tired (which works out well for the user!), but it is more like "nodding" in and out of semi-consciousness. That's really the best way to describe it. It's like a series of times where the user will fall asleep for 30 seconds - a few minutes out of nowhere, and then suddenly snap into wakefulness again. They often are in very uncomfortable positions, too. (because they were not really planning or expecting to be sleeping!)..the term can also sometimes be heard with opiate-based pills, but generally it is specific for being high on heroin.
After shooting alot of H, i could see by the uncomfortable way he was sitting-with his head hanging all limp towards the ground- that he must be nodding off!

"Yesterday we did a few bags and after a few minutes, we were all nodding off."
by dollyheart December 2, 2007
To pass in and out of conciseness within a few seconds from doing too much heroin.
"What's up with Ted? He keeps trying to talk but then he just passes out and waking up confused?" - Guy 1
"He's just nodding off. He should go a little easier on the herioin.
by harddrugcandy October 22, 2012
When you smoke a grip of heroin and fall in and out of sleep.
I had this crazy ass dream while i was nodding off the other day.
by dope fiend 16 October 30, 2007
to fall asleep usually unintentionally.
I often nod off in class.
The speech was so boring that several people in the audience nodded off before it was finished.
by oliverbr May 16, 2006
verb: nod off is what happens when your eyes and brain disobey you, and begin entering hibernation mode even though you know you should be up and awake. Nodding off happens most often when you sit in a comfortable seat in the back of the room during boring classes with droning old professors. Some people are gifted with the screensaver mode, which they can turn on to cover up the fact that they have nodded off
John Doe: "hey, don't nod-off now! you're in the first row for God's sake!"

Don Joe: "zzzzzzzzz grunt grunt zzzzzzzzz"
by Emperor Harry January 17, 2012
When you sipping lean and trying not to fall asleep
We were sipping syrup and we was nodding off
by Young cuz blood September 23, 2014