weir

noun \ ˈwer , ˈwir \

Updated on: 14 Apr 2018

Definition of weir

1 : a fence or enclosure set in a waterway for taking fish

2 : a dam in a stream or river to raise the water level or divert its flow

See weir defined for English-language learners

See weir defined for kids

Recent Examples of weir from the Web

The water eroded the barren hillside beneath the concrete, leading to fears the weir would collapse and release a 40-foot wall of water that would swamp communities and destroy levies for miles downstream.

— CBS News, "Heavy rain in Northern California may test spillway at nation's tallest dam," 6 Apr. 2018
The water eroded the barren hillside beneath the concrete, leading to fears the weir would collapse and release a 40-foot (12-meter) wall of water that would swamp communities and destroy levies for miles downstream.

— Fox News, "California storm may test spillway at nation's tallest dam," 6 Apr. 2018
The data included creel survey information, annual forage assessments by acoustic and bottom trawls and fish examined at weirs.

— paul a. smith, Milwaukee Journal Sentinel, "Smith: Lake Michigan chinook and alewife are near the desired balance, a new report says," 28 Mar. 2018
Throughout the summer of 2018, our staff will use weirs and aerial surveys to gauge run strength to assess if the closure might be modified inseason.

— sam cotten, Anchorage Daily News, "Why the state decided to shut down or restrict king salmon fishing in the Susitna River drainage," 14 Mar. 2018
The 220-acre lagoon at the border of Oceanside and Carlsbad has a weir, or low dam, at the mouth near the beach that keeps seawater out and freshwater in.

— phil diehl, sandiegouniontribune.com, "SANDAG wants another month to review Buena Vista Lagoon project," 20 Feb. 2018
Eggold said Wisconsin and the other state and tribal agencies on Lake Michigan will receive the latest information, including the weight of female age 3 fish returning to weirs, at the March meeting.

— paul a. smith, Milwaukee Journal Sentinel, "Smith: Alewife hit a record low in Lake Michigan in 2017," 21 Feb. 2018
Components include: a drainage pipe from Bayou Chinchuba into the pond; construction of a weir connecting the existing pond; excavation; construction of a wrap-around berm; installation of a bubbler within the pond; fencing and sod.

— robert rhoden, NOLA.com, "Pond near Mandeville to improve water quality, drainage capacity," 2 Feb. 2018
The idea of removing the weir has long polarized North County residents.

— phil diehl, sandiegouniontribune.com, "County's only freshwater lagoon may be opened to sea," 25 Jan. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'weir.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of weir

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.

NEW! Time Traveler

First Known Use: before 12th century

See Words from the same year