/ Dictionary / Index E eustasy: Meaning and Definition of Find definitions for: eu•sta•sy Pronunciation: (y'stu-sē), [key] — pl. -sies. any uniformly global change of sea level that may reflect a change in the quantity of water in the ocean, or a change in the shape and capacity of the ocean basins. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Eustacia eustele Related Content Daily Word Quiz: labyrinth Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language