a special or distinctive mark, token, or device worn as a sign of allegiance, membership, authority, achievement, etc.

a police badge; a merit badge.

any emblem, token, or distinctive mark

He considered a slide rule as the badge of an engineering student.

a card bearing identifying information, as one's name, symbol or place of employment, or academic affiliation, and often worn pinned to one's clothing.

to furnish or mark with a badge.

noun

brand , cordon , device , identification , insignia , mark , marker , medallion , motto , pin , ribbon , scepter , shield , sign , stamp , symbol , token , medal , evidence , index , indication , indicator , manifestation , note , signification , symptom , witness , brassard , cognizance , emblem , ensign , kudos , laurels , plaque , star