tributary vs affluent

tributary and affluent both are nouns.

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

As nouns, tributary and affluent are synonyms defined as:

Other synonyms of tributary include confluent, feeder.

tributary (noun)	affluent (noun)
a branch that flows into the main stream	a branch that flows into the main stream
	an affluent person; a person who is financially well off

tributary (adjective)	affluent (adjective)
tending to bring about; being partly responsible for	having an abundant supply of money or possessions of value
paying tribute
(of a stream) flowing into a larger stream