/ Dictionary / Index C cross-react: Meaning and Definition of Find definitions for: cross-re•act Pronunciation: (krôs'rē-akt', kros'-), [key] — v.i. Immunol. to participate in a cross-reaction. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. cross ratio cross-reaction Related Content Daily Word Quiz: wary Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language