/ Dictionary / Index S seroreaction: Meaning and Definition of Find definitions for: se•ro•re•ac•tion Pronunciation: (sēr"ō-rē-ak'shun), [key] — n. Med., any reaction occurring in serum. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. seropositive serosa Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language