An animal of the genus Bos, especially the common species, B. taurus, including the bull, cow, and ox, in their full grown state; esp., an ox or cow fattened for food.
- A full-grown steer, bull, ox, or cow, especially one intended for use as meat.
- The flesh of a slaughtered full-grown steer, bull, ox, or cow.
- Informal Human muscle; brawn.
- Slang A complaint.
- Slang To complain.
- beef up Informal To make or become greater or stronger: beef up the defense budget.