ancillary vs adjuvant

ancillary is not a noun while adjuvant is a noun.

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

As adjectives, ancillary and adjuvant are synonyms defined as:

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

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

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