complement

(noun) a word or phrase used to complete a grammatical construction.

(noun) a complete number or quantity. Example: "A full complement."

(noun) number needed to make up a whole force. Synonyms: full complement. Example: "A full complement of workers."

(noun) something added to complete or embellish or make perfect. Synonyms: accompaniment. Examples: "A fine wine is a perfect complement to the dinner." "Wild rice was served as an accompaniment to the main dish."

(noun) one of a series of enzymes in the blood serum that are part of the immune response.

(noun) either of two parts that mutually complete each other.

(verb) make complete or perfect; supply what is wanting or form the complement to. Example: "I need some pepper to complement the sweet touch in the soup."