/ Dictionary / Index E eurypterid: Meaning and Definition of Find definitions for: eu•ryp•ter•id Pronunciation: (yoo-rip'tu-rid, yu-), [key] — n. any aquatic arthropod of the extinct order Eurypterida, from the Paleozoic Era, closely related to trilobites and scorpions. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: eurypterid (Thesaurus) euryphagous Eurystheus Related Content Daily Word Quiz: ounterfeit Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language