The Collaborative International Dictionary of English v.0.48:
Accessory \Ac*ces"so*ry\, n.; pl. Accessories.
1. That which belongs to something else deemed the principal;
something additional and subordinate. "The aspect and
accessories of a den of banditti." --Carlyle.
2. (Law) Same as Accessary, n.
3. (Fine Arts) Anything that enters into a work of art
without being indispensably necessary, as mere ornamental
Syn: Abettor; accomplice; ally; coadjutor. See Abettor.