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

  • noun Any of various echinoderms of the class Echinoidea, having a soft body enclosed in a rounded, radially symmetrical, calcareous skeleton covered with long spines.

from The Century Dictionary.

  • noun An echinoid; any member of the Echinoidea; a sea-egg or seahedgehog.

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

  • (Zoöl.) Any one of numerous species of echinoderms of the order Echinoidea.

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

  • noun Any of many marine echinoderms, of the class Echinoidea, commonly found in shallow water, having a complex chewing structure named Aristotle's lantern

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

  • noun shallow-water echinoderms having soft bodies enclosed in thin spiny globular shells


from Wiktionary, Creative Commons Attribution/Share-Alike License

sea + urchin (meaning hedgehog), due to the similarity in appearance to the hedgehog.


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