Derogatory prison slang for an individual who participates in a homosexual relationship while incarcerated. The "gump" may be on either the giving or receiving end, and the sexual intercourse may be consensual or forced; usually the latter.
"What a lot of dudes didn't know though was that Gaps was an old gump from way back. Dude was a predator..."
CITATION: Seth "Soul Man" Ferranti, PRISON STORIES (Gorilla Convict Publications, 2005), p. 133