(Noun) To vomit a little in your mouth, and then gulp it down again, usually as the result of seeing something hideous. Can also be used as a unit of measurement in extreme cases.
Guy 1: Did you see that girl's beergut spilling out under her top?
Guy 2: Yes i did, gave me two gulps of swallowback.
Guy 2: Yes i did, gave me two gulps of swallowback.
by andreijizzek July 31, 2010