Source : Webster's Revised Unabridged Dictionary (1913)

Beef \Beef\ (b[=e]f), n. [OE. boef, befe, beef, OF. boef, buef,
   F. b[oe]ef, fr. L. bos, bovis, ox; akin to Gr. boy^s, Skr.
   g[=o] cow, and E. cow. See 2d {Cow}.]
   1. 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.

   Note: [In this, which is the original sense, the word has a
         plural, beeves (b[=e]vz).]

               A herd of beeves, fair oxen and fair kine.
                                                  --Milton.

   2. The flesh of an ox, or cow, or of any adult bovine animal,
      when slaughtered for food.

   Note: [In this sense, the word has no plural.] ``Great meals
         of beef.'' --Shak.

   3. Applied colloquially to human flesh.

Beef \Beef\, a.
   Of, pertaining to, or resembling, beef.

   {Beef tea}, essence of beef, or strong beef broth.

Source : WordNet®

beef
     n 1: cattle that are reared for their meat [syn: {beef cattle}]
     2: meat from an adult domestic bovine [syn: {boeuf}]
     3: informal terms for objecting; "I have a gripe about the
        service here" [syn: {gripe}, {kick}, {bitch}, {squawk}]
     [also: {beeves} (pl)]

beef
     v : complain; "What was he hollering about?" [syn: {gripe}, {grouse},
          {crab}, {squawk}, {bellyache}, {holler}]
     [also: {beeves} (pl)]