brittle star

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of various marine echinoderms of the order Ophiurida having long slender arms.

from The Century Dictionary.

• noun A name of sundry sand-stars, or ophiurians, from their fragility. See cuts under Astrophyton and star-fish.

from the GNU version of the Collaborative International Dictionary of English.

• (Zoöl.) Any species of ophiuran starfishes. See ophiuroidea.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun any of various echinoderms, of the class Ophiuroidea, that resemble starfish and have long, slender arms that regenerate when snapped off

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun an animal resembling a starfish with fragile whiplike arms radiating from a small central disc
• noun an animal resembling a starfish with fragile whiplike arms radiating from a small central disc