To masturbate or beat off.

Acronym for Big Ass Titties.
Generally referring to a girl with large breasts.

1)A bat is not a rat with wings or a rodent , they are mamals of the order Chiroptera, and are highly intelligent. They are the only mammal that can fly. There are only two types of 'vampire bats' that acually suck blood and they live in South America(mostly).
2)a club used for hitting a ball in various games
3)strike with, or as if with a baseball bat

wank, Masturbate