/ Dictionary / Index E echinoid: Meaning and Definition of Find definitions for: e•chi•noid Pronunciation: (i-kī'noid, ek'u-noid"), [key] — adj. belonging or pertaining to the class Echinoidea, comprising mainly sea urchins and sand dollars. —n. any echinoderm of the Echinoidea. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. echinodermatous echinulate Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language