Source : Webster's Revised Unabridged Dictionary (1913)

Brittle star \Brit"tle star`\ (br[icrt]"t'l st[aum]r`),
   (Zo["o]l.)
   Any species of ophiuran starfishes. See {Ophiuroidea}.

Source : WordNet®

brittle star
     n : an animal resembling a starfish with fragile whiplike arms
         radiating from a small central disc [syn: {brittle-star},
          {serpent star}]