conjunctive vs united

conjunctive is a noun but united is not a noun.

Word	Noun	Adjective	Verb	Adverb
conjunctive	Yes	Yes	No	No
united	No	Yes	No	No

As adjectives, conjunctive and united are synonyms defined as:

Other synonyms of conjunctive include concerted, conjunct, cooperative.

conjunctive (noun)	united (noun)
an uninflected function word that serves to conjoin words or phrases or clauses or sentences

conjunctive (adjective)	united (adjective)
serving or tending to connect	characterized by unity; being or joined into a single entity
involving the joint activity of two or more	of or relating to two people who are married to each other
	involving the joint activity of two or more