adjuvant vs appurtenant

adjuvant is a noun but appurtenant is not a noun.

Word	Noun	Adjective	Verb	Adverb
adjuvant	Yes	Yes	No	No
appurtenant	No	Yes	No	No

As adjectives, adjuvant and appurtenant are synonyms defined as:

Other synonyms of adjuvant include accessory, adjunct, ancillary, auxiliary.

adjuvant (noun)	appurtenant (noun)
an additive that enhances the effectiveness of medical treatment

adjuvant (adjective)	appurtenant (adjective)
enhancing the action of a medical treatment	furnishing added support
furnishing added support