Source : Webster's Revised Unabridged Dictionary (1913)

Beak \Beak\ (b[=e]k), n. [OE. bek, F. bec, fr. Celtic; cf. Gael.
   & Ir. bac, bacc, hook, W. bach.]
   1. (Zo["o]l.)
      (a) The bill or nib of a bird, consisting of a horny
          sheath, covering the jaws. The form varied much
          according to the food and habits of the bird, and is
          largely used in the classification of birds.
      (b) A similar bill in other animals, as the turtles.
      (c) The long projecting sucking mouth of some insects, and
          other invertebrates, as in the Hemiptera.
      (d) The upper or projecting part of the shell, near the
          hinge of a bivalve.
      (e) The prolongation of certain univalve shells containing
          the canal.

   2. Anything projecting or ending in a point, like a beak, as
      a promontory of land. --Carew.

   3. (Antiq.) A beam, shod or armed at the end with a metal
      head or point, and projecting from the prow of an ancient
      galley, in order to pierce the vessel of an enemy; a
      beakhead.

   4. (Naut.) That part of a ship, before the forecastle, which
      is fastened to the stem, and supported by the main knee.

   5. (Arch.) A continuous slight projection ending in an arris
      or narrow fillet; that part of a drip from which the water
      is thrown off.

   6. (Bot.) Any process somewhat like the beak of a bird,
      terminating the fruit or other parts of a plant.

   7. (Far.) A toe clip. See {Clip}, n. (Far.).

   8. A magistrate or policeman. [Slang, Eng.]

Source : WordNet®

beak
     n 1: beaklike mouth of animals other than birds (e.g., turtles)
     2: horny projecting mouth of a bird [syn: {bill}, {neb}, {nib},
         {pecker}]
     3: informal terms for the nose [syn: {honker}, {hooter}, {nozzle},
         {snoot}, {snout}, {schnozzle}, {schnoz}]
     v : hit lightly with a picking motion [syn: {peck}, {pick}]