: a fence or enclosure set in a waterway for taking fish
: a dam in a stream or river to raise the water level or divert its flow

Examples of weir in a Sentence

Recent Examples on the Web In the 1950s, a weir was built at Cowichan Lake to provide water storage for a paper mill, storing and releasing water during the dry months. Norimitsu Onishi, New York Times, 30 Aug. 2023 That effort, led by the San Diego Association of Governments, includes removing the weir, or low dam at the ocean outlet, and restoring tidal ocean flows to what has been a freshwater lagoon since the weir was built. Phil Diehl, San Diego Union-Tribune, 27 Nov. 2022 The city controls several weirs where water is diverted. Ian James, Los Angeles Times, 1 Nov. 2023 The Cowichan Watershed Board is pressing for the construction of a bigger weir that would store more water for the dry months, Mr. Rutherford said. Norimitsu Onishi, New York Times, 30 Aug. 2023 The decades-old weir is incapable of providing sufficient water in the era of climate change, said Mr. Rutherford of the Cowichan Watershed Board. Norimitsu Onishi, New York Times, 30 Aug. 2023 The weir was there to prevent the same kind of runaway erosion that would happen if water flowed over the dam itself. Christopher Cox Spencer Lowell, New York Times, 22 June 2023 The Tisdale weir empties river water directly into the Sutter Bypass. Los Angeles Times, 12 Jan. 2023 Eel weirs and fisheries, important to the Whanganui iwi, and other important ecological assets were destroyed or severely damaged. Debra Utacia Krol, The Arizona Republic, 18 Feb. 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'weir.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Middle English were, going back to Old English wer, going back to Germanic *wera- (whence Old Saxon wer, werr "fish trap, dam," Middle High German wer, Old Norse ver "fishing place"), derivative of an Indo-European verb stem *u̯er- "halt, check, avert," whence, from an iterative derivative *u̯or-ei̯e-, Germanic *warjan- (whence Old English werian "to ward off, protect," Old Saxon, "to hinder, prevent," Old High German weren, werren "to hinder, defend," Old Norse verja "to defend, guard," Gothic warjan "to hinder, forbid"); and, with other ablaut derivatives, Greek érymai, érysthai "to ward off, protect, save," Sanskrit vṛṇoti "(s/he) obstructs, prevents"

Note: See note at aperient.

First Known Use

before the 12th century, in the meaning defined at sense 1

Time Traveler
The first known use of weir was before the 12th century

Dictionary Entries Near weir

Cite this Entry

“Weir.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/weir. Accessed 20 Feb. 2024.

Kids Definition


: a fence set in a stream to catch fish
: a dam in a stream to raise the water level or change the direction and course of its flow

Biographical Definition


biographical name

Robert Walter 1803–1889 American painter

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