/ Dictionary / Index G great-grandfather: Meaning and Definition of Find definitions for: great-grand•fa•ther Pronunciation: (grāt"gran'fä"ur, -grand'-), [key] — n. a grandfather of one's father or mother. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: great-grandfather (Thesaurus) great-granddaughter great-grandmother Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language