also accessary, early 15c., "that which is subordinate to something else," also as a legal term, "one aiding in a felony without committing the offense" (as by advising, inciting, concealing), from Late Latin accessorius, from Latin accessor, agent noun of accedere "to approach" (see accede).
Strictly the noun (a person) should be
accessary
accessory
Especially in the visual arts, "object introduced to balance composition or enhance artistic effect" (1540s). Attested from 1896 as "woman's smaller articles of dress;" hence accessorize. Related: Accessorial.
