add-on vs trimmings

add-on and trimmings both are nouns.

Word	Noun	Adjective	Verb	Adverb
add-on	Yes	No	No	No
trimmings	Yes	No	No	No

As nouns, trimmings is a hyponym of add-on; that is, trimmings is a word with a more specific, narrower meaning than add-on:

add-on: a supplementary component that improves capability
trimmings: the accessories that normally accompany (something or some activity)

Other hyponyms of add-on include auto accessory, computer accessory, fitting, fixings.

add-on (noun)	trimmings (noun)
a component that is added to something to improve it	the accessories that normally accompany (something or some activity)
a supplementary component that improves capability
a software module that extends or enhances the capabilities of an existing application