the proportion of a person's rump to the rest of their body.
Wow, that girl must have an ass fraction of at least a fifth!
1.)A pathethetic person who is being a real jerk. 2.) any driver on the road other than yourself that is preventing your expedient travel from point a to point b 3.) Any customer.
Derived from a play on words for ass "whole". When using insert the appropriate fraction in the insult
<A> don't be an ass half.
<B>What did you call me?
<A>An ass half, because you are so pathetic it would take two of you to make an ass whole.