/ Dictionary / Index G gamma-ray astronomy: Meaning and Definition of Find definitions for: gam'ma-ray astron"omy Pronunciation: (gam'u-rā"), [key] the branch of astronomy that deals with the study of celestial objects by means of the gamma rays that come from them. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. gamma ray gammer Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language