a pejorative term, can be used to belittle or insult someone. Can also be used in place of many other unrelated words; he jassed up his knee pretty badly.
he really jassed that one up.
he pulled a jass.
South Korean k-pop group member Joy/Park Sooyoung from Red Velvet has the perfect body. One of the few kpop girls called thick that actually is thick. Joy + ass
Remember that girl who got shocked by jass? Same.
Not only can in be used in the sense Robert has outlined, but it may also be used in languages other than English.
Krauton besukken da Jassein.
Il y a un Jass.
is the slang use of "Yes" but more exciting answered, used mostly between teens; the spelling of the word can be having one or multiple "S" at the end.
Person 1 : Are You Coming to the party?
Person 2: Jass Girl.
dag, that girl has gotz sum jass.
yo rob, did u hit up that jass?
yo shaniqua has got sum bik-ass jass