Tributary - online puzzles

A tributary or affluent is a stream or river that flows into a larger stream or main stem (or parent ) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river drain the surrounding drainage basin of its surface water and groundwater, leading the water out into an ocean.

A confluence, where two or more bodies of water meet together, usually refers to the joining of tributaries.

The opposite to a tributary is a distributary, a river or stream that branches off from and flows away from the main stream. Distributaries are most often found in river deltas.