adjunct

(noun) something added to another thing but not an essential part of it.

(noun) a person who is an assistant or subordinate to another.

(noun) a construction that can be used to extend the meaning of a word or phrase but is not one of the main constituents of a sentence.

(adj) furnishing added support. Synonyms: accessory, ancillary, adjuvant, appurtenant, auxiliary. Examples: "An ancillary pump." "An adjuvant discipline to forms of mysticism." "The mind and emotions are auxiliary to each other."

(adj) of or relating to a person who is subordinate to another. Synonyms: assistant.