adj.
1.acting as or providing a complement (something that completes the whole)
2.of words or propositions so related that each is the negation of the other
3.of or relating to or suggestive of complementation complementary n.
1.either one of two chromatic colors that when mixed together give white (in the case of lights) or gray (in the case of pigments)
Idiom of the Day
trade in (something) or trade (something) in
to exchange something old or used for something new
My friend traded in his old car for a new one.