accessory vs fitting

accessory and fitting both are nouns.

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

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

Other hyponyms of accessory include auto accessory, computer accessory, fixings, trimmings.

accessory (noun)	fitting (noun)
a supplementary component that improves capability	putting clothes on to see whether they fit
clothing that is worn or carried, but not part of your main clothing	a small and often standardized accessory to a larger system
someone who helps another person commit a crime	(usually in the plural) furnishings and equipment (especially for a ship or hotel)
	making or becoming suitable; adjusting to circumstances

accessory (adjective)	fitting (adjective)
furnishing added support	being precisely fitting and right
aiding and abetting in a crime	in harmony with the spirit of particular persons or occasion