conducive vs tributary

conducive is not a noun while tributary is a noun.

Word	Noun	Adjective	Verb	Adverb
conducive	No	Yes	No	No
tributary	Yes	Yes	No	No

As adjectives, conducive and tributary are synonyms defined as:

conducive and tributary: tending to bring about; being partly responsible for

Other synonyms of conducive include contributing, contributive, contributory.

conducive (noun)	tributary (noun)
	a branch that flows into the main stream

conducive (adjective)	tributary (adjective)
tending to bring about; being partly responsible for	tending to bring about; being partly responsible for
	paying tribute
	(of a stream) flowing into a larger stream