A skanky, or particularly un-kooth dressed female individual with an ass that blows or jiggles in the wind. Jitter Asses, are usually seen waiting on corners for buses or other modes of transportation while also being oblivious to the fact that their sexual nature is being exploited by their clothing, and intelligence level.
Lisa: John, did you see that girl with her ass blowing in the wind? That was such a Jitter Ass.
John: Where? the Girl with the tight athletic pants and low intelligence level?
Lisa: Yes John, they are everywhere.