The Collaborative International Dictionary of English v.0.48:

Claw \Claw\ (kl[add]), n. [AS. clawu, cl[=a], cle['o]; akin to
   D. klaauw, G. klaue, Icel. kl[=o], Sw. & Dan. klo, and perh.
   to E. clew.]
   1. A sharp, hooked nail, as of a beast or bird.
      [1913 Webster]

   2. The whole foot of an animal armed with hooked nails; the
      pinchers of a lobster, crab, etc.
      [1913 Webster]

   3. Anything resembling the claw of an animal, as the curved
      and forked end of a hammer for drawing nails.
      [1913 Webster]

   4. (Bot.) A slender appendage or process, formed like a claw,
      as the base of petals of the pink. --Gray.
      [1913 Webster]

   Claw hammer, a hammer with one end of the metallic head
      cleft for use in extracting nails, etc.

   Claw hammer coat, a dress coat of the swallowtail pattern.
      [Slang]

   Claw sickness, foot rot, a disease affecting sheep.
      [1913 Webster]

WordNet (r) 3.0 (2006):

claw hammer
    n 1: a hammer with a cleft at one end for pulling nails [syn:
         carpenter's hammer, claw hammer, clawhammer]