(count)
1 : something added to something else to make it more useful, attractive, or effective
fashion/clothing accessories such as scarves, handkerchiefs, bracelets, and rings
automotive accessories
computer accessories
2 : law : someone who helps another person commit a crime
He is wanted as an accessory to murder.
She was charged as an accessory before/after the fact. (=someone who helps a criminal before/after a crime has been committed)