Accessory a. : 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.

Accessory n. : That which belongs to something else deemed the principal; something additional and subordinate.

Accessory n. : Same as Accessary, n.

Accessory n. : Anything that enters into a work of art without being indispensably necessary, as mere ornamental parts.

Example:


Taxonomy
accessory, crime, offence, commission, criminal, accessory before the fact, accessory after the fact, offense, defendant, accomplice, jurisdictions, commit a crime, rea, encouragement, agreement, counselling, complicity, presence.

Defination from the web:
accessory and a principal is a question of fact and degree: ... The test to distinguish a joint principal from an accessory is whether the defendant independently contributed to causing the actus reus rather ...