1. A supplementary component; SYN. appurtenance, supplement.
2. Additional clothing that is worn or carried, but not part of one's main clothing (such as belts, scarves, or handbags); SYN. accoutrement, accouterment.
3. Someone who helps another person commit a crime; SYN. accomplice, accessary.

ETYM Latin accessorius. Related to Access, Accessary.
Relating to something that is added but is not essential; SYN. adjunct, ancillary, adjuvant, appurtenant, auxiliary, subsidiary.
1. Aiding and abetting in a crime
2. Furnishing added support

See peripheral.

In law, a criminal accomplice who aids in commission of a crime committed by someone else. An accomplice may be either “before the fact” (assisting, ordering, or procuring another to commit a crime) or “after the fact” (giving assistance after the crime). An accomplice present when the crime is committed is an “abettor”.