billabong
/ˈbɪləbɒŋ/noun
- Austral. a branch of a river forming a backwater or stagnant pool, made by water flowing from the main stream during a flood〈澳〉死河（指支流）, 死水潭。
词源
mid 19th cent.: from Wiradhuri bilabang （originally as the name of the Bell River, NSW）, from billa 'water' + bang 'channel that is dry except after rain'.