Meaning of cross-reaction

cross-re•ac•tion

Pronunciation: (krôs'rē-ak'shun kros'-), [key]
— n.
  1. an immunologic reaction between a given antigen and an antibody or lymphokine that is specific for a different antigen resembling the first one.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.