echinoderm (n.) Look up echinoderm at Dictionary.com
1835, from Modern Latin Echinodermata, name of the phylum that includes starfish and sea urchins, from Greek ekhinos "sea urchin," originally "porcupine, hedgehog" (see echidna) + derma (genitive dermatos) "skin" (see derma); so called from its spiky shell.