An emblem (a small piece of plastic or cloth or metal) that signifies your status (rank or membership or affiliation etc.) WordNet 3.0 & Open English WordNet

A badge is a device or accessory, often containing the insignia of an organization, which is presented or displayed to indicate some feat of service, a special accomplishment, a symbol of authority granted by taking an oath, a sign of legitimate employment or student status, or as a simple means of identification. Wikipedia

Physical or digital insignia indicating membership, rank or accomplishment Wikidata

A simple accessory that can be attached to clothing with a pin or fastener, often round and bearing a design, logo or message, and used for decoration, identification or to show political affiliation, etc. OmegaWiki

A distinctive mark, token, sign, emblem or cognizance, worn on one's clothing, as an insignia of some rank, or of the membership of an organization. Wiktionary

Distinctive mark. Wiktionary (translation)