n. & adj. (also accessary)
n. (pl. -ies) 1 an additional or extra thing. 2 (usu. in pl.) a a small attachment or fitting. b a small item of (esp. a woman's) dress (e.g. shoes, gloves, handbag). 3 (often foll. by to) a person who helps in or knows the details of an (esp. illegal) act, without taking part in it.
adj. additional; contributing or aiding in a minor way; dispensable. accessory before (or after) the fact a person who incites (or assists) another to commit a crime. accessorial adj.
[ med.L accessorius (as ACCEDE) ]