a river or stream that flows into a larger river or a lake （流入大河或湖泊的）支流 
Extra ExamplesTopics Geographyc2The Thames is fed by several small tributaries. 泰晤士河由几条小支流汇合而成。 a tributary stream 支流 Through northern Sudan and Egypt, the Nile is joined by no tributary, flowing as it does through pure desert. 穿过苏丹北部和埃及，尼罗河没有支流汇入，就像流过纯净沙漠一样。 We need to monitor the water quality of the tributaries that feed the lake. 我们需要监测注入湖中各支流的水质。
Oxford Collocations Dictionaryadjective- main
- major
- drain something
- drain into something
- feed something
- …
- river
- stream
Word Originlate Middle English (originally referring to a person or state that pays tribute to another state or ruler): from Latin tributarius, from tributum, neuter past participle (used as a noun) of tribuere ‘assign’ (originally ‘divide between tribes’), from tribus ‘tribe’. The current sense dates from the early 19th cent.
