accessary

accessary, accessory

These two words come by different routes from the same Latin source of our word accede. In AmE, accessory is dominant both as a noun and as an adjective, and it has fast become so now in BrE, although accessary is still used occasionally (where before it was used invariably) as a term in law in both varieties. But -ory is preferable in all meanings:

• As the one person who knew of their illegalities I felt I was becoming an accessory after the fact —S. Unwin, 1960

• If he buried the captain, as he says, he's an accessory —R. Macdonald, 1971

• Accessory ideas associated with the principal idea —M. Cohen, 1977.

• An accessory role is played by another cellular enzyme —Health news release, AmE 2005 [OEC].

As a noun, accessory has become widely used in the 20c to refer to smaller articles of dress (gloves, handbag, etc.) or the extras in a motor vehicle (fog-lights, radio, etc.).

• Accessories…may be considered essential to an outfit. —Alison Lurie, 1981.

• Since September 11th, the emphasis has changed from using the flag as a fashion accessory to using it to show solidarity as a country —weblog, AmE 2003 [OEC].