Defined as anyone who goes to the gym and does many reps and sets of a machine improperly. Often used to appear as if they have more strength than what they really do. Usually associated with buff guys or gym rats.
Bro, look at that dude squatting 415 over there, are his knees even bending?...what a half pump chump.
by Brad_yungtaco June 3, 2016
Get the Half Pump Chumpmug.