Main Entry: com·ple·men·ta·tion

Pronunciation: \ˌkäm-plə-(ˌ)men-ˈtā-shən, -mən-\

Function: noun

Date: 1942

1 : the operation of determining the complement of a mathematical set
2 : production of normal phenotype in an individual heterozygous for two closely related mutations with one on each homologous chromosome and at a slightly different position