The definition of beef is the flesh of a cow, bull or steer.(noun)
Hamburgers and steaks are each an example of beef.
See beef in Webster's New World College Dictionary
Origin: ME < OFr boef < L bos (gen. bovis), ox (apparently an Oscan-Umbrian cognate form, replacing L *vos) < IE *gwōus < base *gwou-: see cow
See beef in American Heritage Dictionary 4
noun pl. beeves beeves (bēvz) or beef
Origin: Middle English
Origin: , from Old French buef
Origin: , from Latin bōs, bov-; see gwou- in Indo-European roots. Word History: That beef comes from cows is known to most, but the close relationship between the words beef and cow is hardly household knowledge. Cow comes via Middle English from Old English cū, which is descended from the Indo-European root *gwou-, also meaning “cow.” This root has descendants in most of the branches of the Indo-European language family. Among those descendants is the Latin word bōs, “cow,” whose stem form, bov-, eventually became the Old French word buef, also meaning “cow.” The French nobles who ruled England after the Norman Conquest of course used French words to refer to the meats they were served, so the animal called cū by the Anglo-Saxon peasants was called buef by the French nobles when it was brought to them cooked at dinner. Thus arose the distinction between the words for animals and their meat that is also found in the English word-pairs swine/pork, sheep/mutton, and deer/venison. What is interesting about cow/beef is that we are in fact dealing with one and the same word, etymologically speaking.
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