Pronunciation: (kom"plu-mun-tā'shun),[key] —n. 1. See complementary distribution. 2. Genetics.the occurrence of a wild-type phenotype when two closely related, interacting mutant genes are expressed in the same cell.
3. Gram. a. complement (def. 6).
b. the use of grammatical complements.
4. cooperation in lowering tariffs to permit the movement of components among different countries when it is more profitable for each country to produce parts of a product than the whole.