Accompanying as a subordinate; aiding in a secondary way; additional; connected as an incident or subordinate to a principal; contributing or contributory; said of persons and things, and, when of persons, usually in a bad sense; as, he was accessory to the riot; accessory sounds in music.
That which belongs to something else deemed the principal; something additional and subordinate.
Same as Accessary, n.
Anything that enters into a work of art without being indispensably necessary, as mere ornamental parts.