/ Dictionary / Index M macrosporangium: Meaning and Definition of Find definitions for: mac•ro•spo•ran•gi•um Pronunciation: (mak"rō-spu-ran'jē-um), [key] — pl. -gi•a megasporangium. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: macrosporangium (Thesaurus) macrosociology macrospore Related Content Daily Word Quiz: profiterole Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language