/ Dictionary / Index G grand duchy: Meaning and Definition of Find definitions for: grand' duch'y Pronunciation: [key] a territory ruled by a grand duke or grand duchess. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. grand duchess Grand Duchy of Muscovy Related Content Daily Word Quiz: verdant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language