Definition of weir in US English:



  • 1A low dam built across a river to raise the level of water upstream or regulate its flow.

    • ‘Follow the river upstream from the weir for about two hundred yards and you will come to a clearing.’
    • ‘Reduced river flows, brought about by the construction of dams, weirs and water diversions, compound the problem.’
    • ‘King Alfred the Great is said to have responded by building weirs and embankments on the river to lower the water-level, so stranding the Danish fleet upstream.’
    • ‘When levels are low, a weir prevents water from leaving the lake.’
    • ‘The Derwent at Sutton is also worth a visit, with plenty of roach showing in the deeper water upstream of the weir.’
    • ‘Through the extensive studies done in the area we know that raising the weir is the only way to go.’
    • ‘Set in idyllic surroundings, with the sound of the Barrow flowing gently over the weir in the background, the studio is the perfect location for an artist.’
    • ‘‘It's such a pity, that with the whole nation short of power, the water is simply flowing over the weir,’ he says.’
    • ‘Mixed news from the Galway Fishery this week, as 13 open gates on the weir meant winter levels in the river.’
    • ‘After considering a voluntary program last week, the decision to impose tougher restrictions was made on Monday because the flow over the weir had ceased.’
    • ‘If water levels in the river drop, the weirs will be dismantled, he added.’
    • ‘A weir is a dam placed across a river to raise or divert the water, or a fence in a stream to catch or retain fish.’
    • ‘Cllr Clarke welcomed the development and said a walkway across the river at the weirs would be a great attraction.’
    • ‘Upstream of the weir the River Wharfe was glassy smooth with rising trout and cruising ducks, down river the water boiled amongst the smooth white rocks.’
    • ‘Three of four weirs in the river broke, and an influx of sand has left water depths of only two to four inches.’
    • ‘The Environment Agency is to set out its long-term plans for a variety of rivers, weirs and brooks across the north west.’
    • ‘Sometimes on an exceptionally high tide the water flows over the weir causing a tidal effect as far up as Kingston.’
    dam, barrier, dyke, defence, embankment, wall, obstruction, gate, sluice
    View synonyms
    1. 1.1 An enclosure of stakes set in a stream as a trap for fish.
      • ‘The effectiveness of fish weirs was well known throughout Europe.’
      • ‘Men are responsible for line and weir fishing, hunting, gardening, and the felling of trees.’
      • ‘Fishermen use weirs, traps, gill nets, and dip nets for alewives, which they consider one of the easiest fish to catch.’
      • ‘Unlike gill nets, fish weirs were permanent structures that essentially allowed one man to ‘fish’ twenty-four hours a day.’
      • ‘Trouble began in the spring of 1816 when Judge Cooper built a weir, a fish trap, across the St. Jones River to catch migrating shad and herring.’
      • ‘Evolving technologies have included aboriginal spears, nets, and weirs and European purse seines.’
      • ‘Fish, especially Arctic char were caught in weirs and traps and taken using fish spears.’
      • ‘Seines at least collected less mud and debris than weirs and staked gill nets.’
      • ‘Surprisingly, evidence of stone and willow fish weirs, which bridged estuaries and bays as far afield as western Europe and northern American, can still be found.’


Old English wer, from werian ‘dam up’.