/ Dictionary / Index M megakaryoblast: Meaning and Definition of Find definitions for: meg•a•kar•y•o•blast Pronunciation: (meg"u-kar'ē-u-blast"), [key] — n. Cell Biol. a cell that gives rise to a megakaryocyte. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. megajoule megakaryocyte Related Content Daily Word Quiz: placid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language