Chuck means to throw, and also sounds like "chunks" so it's a fun term for throwing up (vomiting). There was a joke (now quite antique) when Princess Diana was first pregnant. "Do you know what Charles and Diana are going to name their baby? Up. Because then they can be 'Up, Chuck and Di'." (Upchuck and die, which was funny then because the going insult in those days was "eat shit and die.") You can also recite, a la "How much wood could a woodchuck chuck..."...
Eeyew, he's gonna upchuck.
by Sandra Dodd December 29, 2005
1. (v) to vomit
2. (v) In software engineering, the word is often used when a program terminates abnormally.
1. I drank 3 cases of beer and I upchucked for days.

2. "Hey, man, wake up! Your program just upchucked and the supervisors want it fixed now!"
by Robert E. Porter, Jr. August 20, 2006
to vomit, to empty ones stomach through one's mouth
Don't you upchuck on the rug.
by The Return of Light Joker June 19, 2008
1. simply it means to throw up, to "puke your guts out". See the tags for more synonyms.
1. when I was in college I was reading the university newspaper while eating my lunch on the 3rd floor study lounge. Nearby I heard activity going on the same floor. After I finished lunch I went over there and the Student Muslim Organization was holding a vigil/teach-in about what was happening in Bosnia at the time. The details in the videotape, the atrocity accounts told, and the pictures were a bit much. I felt icky inside and ready to upchuck.

2. All the sorry-ass boy bands and pop tart "divas" make me wanna upchuck when their shit is played and broadcast like some sort of Orwellian Newspeak.

3. When the cops busted into the hotel to see if Marie Provost was OK they saw her deceased body and noticed that her hungry little dauschound had partially eaten her hand. This and other things there made the cops upchuck. This story is detailed in a Nick Lowe song. Check it out.

4. I really liked the Stallone flick "First Blood", it was pretty good. The follow-up sequels however are so sick and incredibly stupid they may make you upchuck because of their outright suckability.
by I Saw U2 Live Twice July 31, 2009
1. relating to vomit or vomiting
2. An appropriate name for North Charleston, the ghetto attached to Charleston, SC. North Charleston is clearly up from Charleston on the map. Charleston is often referred to as "Chucktown". Thus "up" and "chuck" forming "Upchuck".
1. Don't upchuck in my car!
2. Remember to lock your doors if you're driving through Upchuck, and don't gaze directly at any of its inhabitants.
by koalaroo May 19, 2008
Upchuck muff is when an individual is eating out a woman and throws up in her vagina.
"Dude, I was with this girl last night after leaving the bar and, well, lets just say she has an upchuck muff."
by Upchuck muff mike February 24, 2018