/ Dictionary / Index L lymphoblast: Meaning and Definition of Find definitions for: lym•pho•blast Pronunciation: (lim'fu-blast"), [key] — n. Cell Biol. a large, metabolically active lymphocyte shortly before it enters into mitosis. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: lymphoblast (Thesaurus) lympho- lymphocyte Related Content Daily Word Quiz: tenacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language