ancillary vs adjunct

ancillary is not a noun while adjunct is a noun.

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

As adjectives, ancillary and adjunct are synonyms defined as:

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

ancillary (noun)	adjunct (noun)
	a construction that can be used to extend the meaning of a word or phrase but is not one of the main constituents of a sentence
	something added to another thing but not an essential part of it
	a person who is an assistant or subordinate to another

ancillary (adjective)	adjunct (adjective)
furnishing added support	of or relating to a person who is subordinate to another
	furnishing added support