1.InterjectionIndicates disapproval, disagreement, or disbelief, often with a tone of disregard, disdain, or disgust, referring to the buttocks.
"She'll use my money to buy a new car, my ass!; You're his brother, my ass! You look nothing alike."
2.PronounI; me; myself; oneself in the third person.
"My boss screwed up again, and of course it's my ass that has to deal with it.; Now I gotta drag my ass to work. He says it's fine, but get real—you know it'd be *my* ass on the hook, if anything happened."