When you urinate, after sexual intercourse or masturbation in which you have achieved ejaculation, Jiss is the chunky-ish white semen left over that gets shot out while said urination is taking place.
We've all seen a jiss I'm sure. Also known as the gusher, the squirter, the juicer. This term is used for when a woman, gets butt nekkid squats down and ejaculates a hugely long triumphant ribbon of clear pisslike and jizzlike liquid during orgasm. However... its not jizz... its not piss.... ITS JISS
"I had this girl over the other night and damn i got JISSED on!"