The term "belonger" refers to someone or something that is a part of a group or community. Some synonyms for this term could include "member," "affiliate," "participant," "inhabitant," or "resident." Each of these words suggests a level of involvement or connection to a particular group or place. Other options could include "comrade," "colleague," "fellow," or "peer," which highlight the social or professional aspects of belonging. Ultimately, the synonym chosen will depend on the context in which the term is used and the specific connotations desired.