From Longman Dictionary of Contemporary Englishtributarytrib‧u‧ta‧ry /ˈtrɪbjətəri $ -teri/ noun (plural tributaries) [countable] PGa stream or river that flows into a larger river
Examples from the Corpus
tributary• I was on Lyne Water at the time, a tributary of the River Tweed.• Fed by different tributaries, as Don F6lix was saying before when he was waxing poetic.• They started in small workshops in the upper course valleys of the River Don and its tributaries, such as the River Sheaf.• Dace hard to find, even the Llynfi tributary at Glasbury is giving little.• Allen Water, a major tributary of the South Tyne, offered perfect dry fly fishing.• The principal river systems and their major tributaries are described below.• Settlement was concentrated in fishing villages on the tributaries of the Snake, Clearwater and Salmon Rivers. 