a.

1. 纳贡的，附庸的，从属的[（+to）]
   a tributary nation

   进贡国

2. 辅助的
3. 支流的
   There was a tributary road near the end of the village.

   村的尽头有条岔道。

n.[C]

1. 进贡国，附庸国[（+to）]
2. 进贡者
3. 支流
   The Missouri River is the chief tributary of the Mississippi.

   密苏里河是密西西比河的主要支流。

n.

1. a river or stream flowing into a larger river or lake.
2. historical a person or state that pays tribute to another state or ruler.