/ Dictionary / Index G graywacke: Meaning and Definition of Find definitions for: gray•wacke Pronunciation: (grā'wak", -wak"u), [key] — n. a dark-gray coarse-grained wacke. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. gray urn gray water Related Content Daily Word Quiz: procrastinate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language