hammerhead

from WordNet (r) 3.0 (2006)
hammerhead
    n 1: a stupid person; these words are used to express a low
         opinion of someone's intelligence [syn: {dunce},
         {dunderhead}, {numskull}, {blockhead}, {bonehead},
         {lunkhead}, {hammerhead}, {knucklehead}, {loggerhead},
         {muttonhead}, {shithead}, {dumbass}, {fuckhead}]
    2: the striking part of a hammer
    3: medium-sized live-bearing shark with eyes at either end of a
       flattened hammer-shaped head; worldwide in warm waters; can
       be dangerous [syn: {hammerhead}, {hammerhead shark}]
    
from The Collaborative International Dictionary of English v.0.48
Hammerhead \Ham"mer*head`\ (-h[e^]d`), n.
   1. (Zool.) A shark of the genus {Sphyrna} or {Zyg[ae]na},
      having the eyes set on projections from the sides of the
      head, which gives it a hammer shape. The {Sphyrna
      zyg[ae]na} is found in the North Atlantic. Called also
      {hammer fish}, and {balance fish}.
      [1913 Webster]

   2. (Zool.) A fresh-water fish; the stone-roller.
      [1913 Webster]

   3. (Zool.) An African fruit bat ({Hypsignathus monstrosus});
      -- so called from its large blunt nozzle.
      [1913 Webster]
    

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