What is the meaning of Tributary?

A natural water stream that flows into a larger river or other body of water.

A vein which drains into another vein.

A nation, state, or other entity that pays tribute.

Related to the paying of tribute.

Subordinate; inferior.

Yielding supplies of any kind; serving to form or make up, a greater object of the same kind, as a part, branch, etc.; contributing.

Source: wiktionary.org