key fob vs accoutrement

key fob and accoutrement both are nouns.

Word	Noun	Adjective	Verb	Adverb
key fob	Yes	No	No	No
accoutrement	Yes	No	No	No

As nouns, accoutrement is a hypernym of key fob; that is, accoutrement is a word with a broader meaning than key fob:

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

Other hypernyms of key fob include accessory, accouterment.

key fob (noun)	accoutrement (noun)
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