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

moccasin \moc"casin\, n. an indian word. algonquin makisin.
   sometimes written moccason.
   1. a shoe made of deerskin, or other soft leather, the sole
      and upper part being one piece. it is the customary shoe
      worn by the american indians.
      1913 webster

   2. zool. a poisonous snake of the southern united states.
      the water moccasin ancistrodon piscivorus syn.
      agkistrodon piscivorus, also called cottonmouth and
      cottonmouth water moccasin is usually found in or near
      water. above, it is olive brown, barred with black;
      beneath, it is brownish yellow, mottled with darker. the
      upland moccasin is ancistrodon atrofuscus. they resemble
      rattlesnakes, but are without rattles.
      1913 webster

   moccasin flower bot., a species of lady's slipper
      cypripedium acaule found in north america. the lower
      petal is two inches long, and forms a rose-colored
      moccasin-shaped pouch. it grows in rich woods under
      coniferous trees.
      1913 webster
see also:
moccason ancistrodon piscivorus agkistrodon piscivorus cottonmouth cottonmouth water moccasin ancistrodon atrofuscus 
moccasin flower cypripedium acaule 

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

cottonmouth \cottonmouth\ n.
   venomous semiaquatic snake agkistrodon piscivorus of
   swamps in southern u.s.; -- called also water moccasin,
   cottonmouth moccasin, and cottonmouth water moccasin. it
   grows to a length of about 4 feet. the name refers to the
   whiteness of the lips and inside of the mouth.

   syn: water moccasin, cottonmouth moccasin, agkistrodon
        piscivorus.
        wordnet 1.5 +pjc
see also:
agkistrodon piscivorus water moccasin cottonmouth moccasin cottonmouth water moccasin agkistrodon piscivorus 

[3] : WordNet (r) 2.0

cottonmouth
     n : venomous semiaquatic snake of swamps in southern united
         states syn: water moccasin, cottonmouth moccasin, agkistrodon
         piscivorus
see also:
water moccasin cottonmouth moccasin agkistrodon piscivorus 

Cottonmouth >> C Words
Cottonmouth, definition of term: Cottonmouth
cottonmouth_pag1.html