Origin: Latin suffix -ary
Tributary has 6 different meanings across 2 categories:
A natural water stream that flows into a larger river or other body of water.
"The small creek we crossed on our hike turned out to be a tributary feeding directly into the mighty Ohio River."
(of a stream) flowing into a larger stream
"The small creek we crossed is actually just a tributary of the mighty river below."
tending to bring about; being partly responsible for
"working conditions are not conducive to productivity"
"the seaport was a contributing factor in the growth of the city"
"a contributory factor"
Related to the paying of tribute.
"The ancient king demanded that every neighboring village send him a portion of their harvest as a tributary payment for protection."