complementary
n. B2 Upper Intermediate US //ˌkɑmpɫəˈmɛntɹi// UK //kˌɒmplɪmˈɛntəɹi// com·ple·men·tary
n. completing or going well with something else. You use it to describe two things that fit together perfectly.
n. forming a complete whole when combined with another element; mutually enhancing or completing.
The red wine is a complementary drink for this meal.
Blue and orange are complementary colors that create strong visual contrast.
The two policies are complementary, addressing different aspects of the same social problem without overlapping in their specific mandates.
From complement + -ary. Piecewise doublet of complimentary.