/ Dictionary / Index G gill filament: Meaning and Definition of Find definitions for: gill' fil"ament Pronunciation: (gil), [key] one of the threadlike processes forming the respiratory surface of a gill. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Gillette gill fungus 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