adjunct
Definitions
A thing added to something else as a supplementary rather than an essential part.
A person who is joined or associated with another in a subordinate or temporary capacity.
A word or phrase that modifies the meaning of a sentence or a part of a sentence.
Examples
The university hired an adjunct professor to teach the introductory psychology course.
The new policy serves as an adjunct to the existing safety regulations.
Synonyms
addition supplement accessory attachment appendage addendum auxiliary