Breadcrumb Home > Dictionary > Index V vitamin G: Meaning and Definition of Find definitions for: vitamin G Pronunciation: [key] riboflavin. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. vitamin E vitamin H ✖ Related Content Daily Word Quiz: acronym Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language