Origin: Latin suffix -ory
Accessory has 7 different meanings across 2 categories:
clothing that is worn or carried, but not part of your main clothing
"She added a red scarf and a wide-brimmed hat as accessories to her simple black dress."
a supplementary component that improves capability
Something that belongs to part of another main thing; something additional and subordinate, an attachment.
In plain English: An accessory is an extra item that goes with something else to make it look better or work more effectively.
"She wore a bright red scarf as a fashion accessory to her coat."
Usage: Use accessory to refer to a smaller item that complements or completes a larger object, such as jewelry worn with clothing or a device attached to a vehicle. Avoid using it for the main component itself, which should be described as the primary item or central piece.
Having a secondary, supplementary or subordinate function by accompanying as a subordinate; aiding in a secondary way; being additional; being connected as an incident or subordinate to a principal; contributing or being contributory. Said of people and things, and, when of people, usually in a bad sense
"The corrupt politician was arrested along with his accessory who helped him hide the stolen funds."
In plain English: An accessory is something extra that goes with a main item to make it look better or work more effectively.
"The accessory details on her outfit made the simple dress look elegant."
Usage: As an adjective, use "accessory" to describe something that is secondary or supplementary to a main item, such as an accessory feature on a phone. When describing people, reserve the term for those who assist in a crime, as it implies a subordinate and often illegal role.
The word comes from the Medieval Latin accessōrius, derived from the Latin accessor, which meant "helper" or "subordinate." It entered English through this lineage, carrying forward its original sense of something added to assist a main item.