柯林斯詞典weir /w??/ (weirs) 1. N-COUNT A weir is a low barrier built across a river in order to control or direct the flow of water. 堰 返回 weir劍橋詞典a wall built under the water across a river , over which the water flows from one level to another in a controlled way 堰；攔河垻 返回 weir