/ Dictionary / Index B blastoma: Meaning and Definition of Find definitions for: blas•to•ma Pronunciation: (bla-stō'mu), [key] — pl. -mas, -ma•ta a tumor originating from undifferentiated embryonic cells and having little or no connective tissue. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: blastoma (Thesaurus) blastogenesis blastomere Related Content Daily Word Quiz: fabricate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language