Толковый словарь английского языка - complementary

adjective Date: 1829 relating to or constituting one of a pair of contrasting colors that produce a neutral color when combined in suitable proportions, serving to fill out or complete, mutually supplying each other's lack, being complements of each other , characterized by the capacity for precise pairing of purine and pyrimidine bases between strands of DNA and sometimes RNA such that the structure of one strand determines the other, complementarily adverb complementariness noun ~ noun