/ Dictionary / Index G galactan: Meaning and Definition of Find definitions for: ga•lac•tan Pronunciation: (gu-lak'tun, -tan), [key] — n. Biochem. any of the class of hexosans, as agar, that yield galactose upon hydrolysis. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. galact- galactic Related Content Daily Word Quiz: endear Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language