kick someone's ass verb2 •(US, Canada) To kick someone in the buttocks.Then the horse kicked Pat's ass. Needless to say, she was not happy! •(US, Canada) To clobber someone; to beat someone severely.With their star quarterback back on the field, the Doves are going to kick the Pigeons' asses tonight. formskicked someone's ass · kicking someone's ass · kicks someone's ass