/ Dictionary / Index E eugeosyncline: Meaning and Definition of Find definitions for: eu•ge•o•syn•cline Pronunciation: (y-jē"ō-sing'klīn, -sin'-), [key] — n. Geol. a former marine zone, bordering an ocean basin, marked by very thick deposits of sediment in which the products of volcanic activity are associated with clastic sediments. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. eugenol Euglena* Related Content Daily Word Quiz: knead Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language