[i-kahy-nuh-durm, ek-uh-nuh-] 
| any marine animal of the invertebrate phylum Echinodermata, having a radiating arrangement of parts and a body wall stiffened by calcareous pieces that may protrude as spines and including the starfishes, sea urchins, sea cucumbers, etc. |
| e·chi·no·derm (ĭ-kī'nə-dûrm') n. Any of numerous radially symmetrical marine invertebrates of the phylum Echinodermata, which includes the starfishes, sea urchins, and sea cucumbers, having an internal calcareous skeleton and often covered with spines. [From New Latin Echinodermata, phylum name : echino- + -dermata, -skinned (from Greek derma, dermat-, skin; see -derm).] e·chi'no·der'mal, e·chi'no·der'ma·tous (-dûr'mə-təs) adj. |