[ kom-pluh-muh n-tey-shuh n ]
/ ˌkɒm plə mənˈteɪ ʃən /


Genetics. the occurrence of a wild-type phenotype when two closely related, interacting mutant genes are expressed in the same cell.
  1. complement(def 6).
  2. the use of grammatical complements.
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.

Origin of complementation

First recorded in 1935–40; complement + -ation Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Examples from the Web for complementation

British Dictionary definitions for complementation

/ (ˌkɒmplɪmɛnˈteɪʃən) /


the act or process of forming a complement
genetics the combination of two homologous chromosomes, each with a different recessive mutant gene, in a single cell to produce a normal phenotype. The deficiency of one homologue is supplied by the normal allele of the other
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for complementation

[ kŏm′plə-mən-tāshən, -mĕn- ]


Functional interaction between two defective viruses permitting replication under conditions inhibitory to the single virus.
Interaction between two genetic units, one or both of which are defective, permitting the organism containing these units to function normally, whereas it could not do so if one unit were absent.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.