/ Dictionary / Index G galacto-: Meaning and Definition of Find definitions for: galacto- Pronunciation: [key] a combining form meaning “milk,” used in the formation of compound words: galactopoietic. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. galactin galactoid Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language