A measure of hotness which implies that a woman is cute, but not above that level of cuteness which one may find at a bowling alley. The implication is that even though a trashy, low-class girl may be do-able, she should also be held responsible for her trashiness. It's a combo of a compliment and an insult.
-Hey bro - how about that hot-ass girl who gave up the crusty-dusty last night??
-Awww man - not bad, I guess she was bowling alley hot.