[ ɪ'kʌɪnə(ʊ)də:m , 'ɛkɪn- ]
■ noun Zoology a marine invertebrate of the phylum Echinodermata, which includes starfishes, sea urchins, brittlestars, crinoids, and sea cucumbers.
Origin
from mod. L. Echinodermata , from Gk ekhinos 'hedgehog, sea urchin' + derma 'skin'.