weir
/wɪə(r)/noun
1- a low dam built across a river to raise the level of water upstream or regulate its flow（为提高上游水位或调节流量而建的）堰, 拦河坝, 导流坝。
1.1
- an enclosure of stakes set in a stream as a trap for fish（用来阻挡游鱼以便捕捉的）鱼梁, 鱼簖。
词源
Old English wer, from werian 'dam up'.