/ Dictionary / Index M molecular astronomy: Meaning and Definition of Find definitions for: molec'ular astron'omy Pronunciation: [key] the branch of astronomy dealing with the study of molecules in space. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. molecular molecular beam Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language