Real Dictionary

-ass in American English
added to adjectives as an intensifier

ass
countable noun: An ass is an animal which is related to a horse but which is smaller and has long ears.
countable noun: If you describe someone as an ass, you think that they are silly or do silly things.
countable noun: Your ass is your bottom.

ass in American English 1
noun: a long-eared, slow, patient, sure-footed domesticated mammal, Equus asinus, related to the horse, used chiefly as a beast of burden

ass in American English 2
noun: the buttocks

ass in British English 1
noun: either of two perissodactyl mammals of the horse family (Equidae), Equus asinus ( African wild ass) or E. hemionus ( Asiatic wild ass). They are hardy and sure-footed, having longer ears than the horse

ass in British English 2
noun: the buttocks

ass. in American English
abbreviation: assistant