/ Dictionary / Index G gill book: Meaning and Definition of Find definitions for: gill' book" Pronunciation: (gil). [key] See Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. gill bar gill box Related Content Daily Word Quiz: mamba Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language