[1] : The Collaborative International Dictionary of English v.0.48

keyhole \key"hole`\, n.
   1. a hole or apertupe in a door or lock, for receiving a key.
      1913 webster

   2.
      a carp. a hole or excavation in beams intended to be
          joined together, to receive the key which fastens
          them.
      b mach. a mortise for a key or cotter.
          1913 webster

   keyhole limpet zool., a marine gastropod of the genus
      fissurella and allied genera. see fissurella.

   keyhole saw, a narrow, slender saw, used in cutting
      keyholes, etc., as in doors; a kind of compass saw or fret
      saw.

   keyhole urchin zool., any one of numerous clypeastroid
      sea urchins, of the genera melitta, rotula, and
      encope; -- so called because they have one or more
      perforations resembling keyholes.
      1913 webster
see also:
keyhole limpet fissurella keyhole saw keyhole urchin melitta rotula 
encope 

[2] : WordNet (r) 2.0

keyhole
     n : the hole where a key is inserted

[3] : Moby Thesaurus II by Grady Ward, 1.0

28 moby thesaurus words for "keyhole":
   air hole, armhole, blowhole, bullet-hole, bunghole, cringle,
   deadeye, eye, eyelet, gasket, grommet, guide, knothole, loop,
   loophole, manhole, mousehole, peephole, pigeonhole, pinhole,
   placket, placket hole, porthole, punch-hole, spiracle, tap, vent,
   venthole

Keyhole >> K Words
Keyhole, definition of term: Keyhole
keyhole_pag1.html

Keyhole Limpet >> K Words
Keyhole Limpet, definition of term: Keyhole Limpet
keyhole+limpet_pag1.html