/kraws"ri zis"teuhns, kros"-/ , n. Biol.
1. immunologic resistance to the pathogenic effects of a microorganism because of previous exposure to another species or type having cross-reactive antigens.
2. resistance to the effects of a substance, as that of an insect population to an insecticide or a bacterial strain to an antibiotic, stimulated by exposure and adaptation to a similar or related substance.
[ 1945-50 ]