Verb. Stop doing (something). E.g."I'm going to jack in my college course after the vacation, it's too much like hard work." Jackson Pollocks Noun. 1. Testicles. Rhyming slang for 'bollocks'.2. Nonsense, rubbish. Rhyming slang for 'bollocks'.
JACK IN
Meaning of JACK IN in English
Slang English vocab. Английский сленговый словарь. 2012