A stream or river called that flows into a larger stream or river is called a tributary.
Usually a river
Tributary
It is a small stream that leads into a larger stream. (it is spelled tributary)
Those are tributaries. Instead of feeding into an ocean or lake, they meet with a larger river.
Tributary
A tributary.
The smaller stream is a tributary of a larger stream, river or lake.
It is called a tributary.
A tributary.
A Tributary.
Tributary.