/ Dictionary / Index L lymphocytosis: Meaning and Definition of Find definitions for: lym•pho•cy•to•sis Pronunciation: (lim"fu-sī-tō'sis), [key] — n. Pathol. an abnormal increase in the number of lymphocytes in the blood. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: lymphocytosis (Thesaurus) lymphocyte lymphogranuloma 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