(slang, vulgar) I; me; myself; oneself in the third person.

(slang, vulgar) Indicates disapproval, disagreement, or disbelief, often with a tone of disregard, disdain, or disgust, referring to the buttocks.

A beating, sometimes prearranged. / A brutal and decisive defeat of an individual or group of people by another who had thoroughly dominated them in doing so, such as in sports.

bare-bottomed / (informal, by extension) naked, starkers / (informal, by extension) blatant, unashamed

(Canada, US, vulgar, slang) The gluteal cleft.

The onager.

Poorly or incompetently done. / desultory

Produced in an incompetent or desultory manner, or of something lacking in quality or substance; of low rank; incompetent.

simple past tense and past participle of kick ass

Third-person singular simple present indicative form of kick ass