Source : Webster's Revised Unabridged Dictionary (1913)

Basilisk \Bas"i*lisk\, n. [L. basiliscus, Gr. ? little king,
   kind of serpent, dim. of ? king; -- so named from some
   prominences on the head resembling a crown.]
   1. A fabulous serpent, or dragon. The ancients alleged that
      its hissing would drive away all other serpents, and that
      its breath, and even its look, was fatal. See
      {Cockatrice}.

            Make me not sighted like the basilisk. --Shak.

   2. (Zo["o]l.) A lizard of the genus {Basiliscus}, belonging
      to the family {Iguanid[ae]}.

   Note: This genus is remarkable for a membranous bag rising
         above the occiput, which can be filled with air at
         pleasure; also for an elevated crest along the back,
         that can be raised or depressed at will.

   3. (Mil.) A large piece of ordnance, so called from its
      supposed resemblance to the serpent of that name, or from
      its size. [Obs.]

Source : WordNet®

basilisk
     n 1: (classical mythology) a serpent (or lizard or dragon) able
          to kill with its breath or glance
     2: ancient brass cannon
     3: small crested arboreal lizard able to run on its hind legs;
        of tropical America