accessory vs keyfob

accessory and keyfob both are nouns.

Word	Noun	Adjective	Verb	Adverb
accessory	Yes	Yes	No	No
keyfob	Yes	No	No	No

As nouns, keyfob is a hyponym of accessory; that is, keyfob is a word with a more specific, narrower meaning than accessory:

accessory: clothing that is worn or carried, but not part of your main clothing
keyfob: A small object fastened to a key chain or key ring and designed to be comfortably grasped.

Other hyponyms of accessory include belt, furnishing, trappings, key fob.

accessory (noun)	keyfob (noun)
a supplementary component that improves capability	A small object fastened to a key chain or key ring and designed to be comfortably grasped.
clothing that is worn or carried, but not part of your main clothing
someone who helps another person commit a crime

accessory (adjective)	keyfob (adjective)
furnishing added support
aiding and abetting in a crime