A fork of Rural Dictionary
One who is being a complete retard for no apparent reason, also quite similar to asshat.
May also mean one who is a jerk about nothing.
"Damn, Steve is being a real crabass about his fridge, wouldn't let me get near it"
Two Possible Meanings
1. Either the ability to get ass from all women, therefore becoming master of the ass, can be applied as a form of admiration or possibly an insult (usually both).
2. Or a term for one who is skilled in the buttsex, may be applied to homosexuals.
1. "The Assmaster is out again"
2. "Yeah Steve is a real Assmaster isn't he?"