Available Definitions:
1) a. - Paying tribute to another, either from compulsion, as an acknowledgment of submission, or to secure protection, or for the purpose of purchasing peace.
2) a. - Hence, subject; subordinate; inferior.
3) a. - Paid in tribute.
4) a. - Yielding supplies of any kind; serving to form or make up, a greater object of the same kind, as a part, branch, etc.; contributing; as, the Ohio has many tributary streams, and is itself tributary to the Mississippi.
5) n. - A ruler or state that pays tribute, or a stated sum, to a conquering power, for the purpose of securing peace and protection, or as an acknowledgment of submission, or for the purchase of security.
6) n. - A stream or river flowing into a larger river or into a lake; an affluent.