beef / bēf/ • n. 1. the flesh of a cow, bull, or ox, used as food. ∎  (pl. beeves / bēvz/ ) Farming a cow, bull, or ox fattened for its meat. ∎ inf. flesh or muscle, typically when well developed: he needs a little more beef on his bones. ∎ inf. strength or power: he's been brought in to give the team more beef.2. (pl. beefs) inf. a complaint or grievance: he has a beef with American education: it doesn't teach the basics of investing.3. inf. a criminal charge: a drunk-driving beef. • v. [intr.] inf. complain: he was beefing about how the recession was killing the business.PHRASAL VERBS: beef something up inf. give more substance or strength to something: cost-cutting measures are planned to beef up performance.

beef Flesh of the ox (Bos taurus); flesh from young calves is veal. A 150‐g portion of most cuts is a rich source of protein, niacin, iron, and vitamin B₁₂; a good source of vitamin B₂ and copper; a source of vitamins B₁, B₆, and selenium; contains 20–30 g of fat, of which half is saturated (lean part is 5% fat); supplies 350–500 kcal (1470–2100 kJ).

beef flesh of the ox. XIII. ME. boef, beef — AN., OF. boef, buef (mod. bœuf):- L. bovem, nom. bōs ox (see COW1).
Hence beefeater eater of beef; Yeoman of the Guard. XVII.