Something which completes, something which combines with something else to make up a complete whole; loosely, something perceived to be a harmonious or desirable partner or addition.
(grammar) A word or group of words that completes a grammatical construction in the predicate and that describes or is identified with the subject or object.
A nucleotide sequence in which each base is replaced by the complementary base of the given sequence: adenine (A) by thymine (T) or uracil (U), cytosine (C) by guanine (G), and vice versa.