beat someone's ass

verb3

1. •
   (US, vulgar) To thrash someone.
2. •
   (US, vulgar) To beat someone severely.

   • God say spoil the apple, rot the apple, beat the child," some shit like that. Uh-huh, which mean beat your ass. — 1997
3. •
   (US, vulgar) To defeat or trounce someone; to win decisively over someone.

   • We got to do whatever it takes and beat their ass. — 2015