com·ple·men·ta·ry 
(kŏm′plə-mĕntə-rē, -trē)
(kŏm′plə-mĕntə-rē, -trē)adj.
1. Forming or serving as a complement; completing: finally acquired the complementary volumes that made a whole set.
2. Offsetting mutual deficiencies or enhancing mutual strengths: "Creatures with complementary skills flourish in each other's presence" (Richard Dawkins).
3. Of or relating to complementary medicine.
4. Genetics Of or relating to a group of genes that act in concert to produce a specific phenotype.
5. Biochemistry Of or relating to the specific pairing of the purines and pyrimidines between strands of a DNA or an RNA molecule.
6. Physics Of or relating to the hypothesis that underlying properties of entities, especially subatomic particles, may manifest themselves in mutually exclusive forms at different times, depending on the conditions of the observation, and that any physical model that describes entities in terms of one form or the other will be incomplete.
com′ple·menta·ri·ly (-tə-rə-lē, -trə-lē, -mĕn-târə-lē) adv.
com′ple·menta·ri·ness n.