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1. Of words or propositions so related that each is the negation of the other
   "'male' and 'female' are complementary terms"
    
2. Acting as or providing a complement (something that completes the whole)
   - complemental, completing

1. Either one of two chromatic colours that when mixed together give white (in the case of lights) or grey (in the case of pigments)
   "yellow and blue are complementaries";
   - complementary color [US], complementary colour [Brit, Cdn]

Sounds like: complimentary

Derived forms: complementaries

See also: additive, antonymous

Type of: chromatic color [US], chromatic colour [Brit, Cdn], spectral color [US], spectral colour [Brit, Cdn]

Encyclopedia: Complementary