over·​run | \ ˌō-vər-ˈrən , ˌō-və-\
overran\ ˌō-​vər-​ˈran , ˌō-​və-​ \; overrun; overrunning

Definition of overrun

 (Entry 1 of 2)

transitive verb

1a(1) : to defeat decisively and occupy the positions of
(2) : to invade and occupy or ravage
b : to spread or swarm over : infest
2a : to run or go beyond or past the plane overran the runway
b : exceed overrun a budget
c : to readjust (set type) by shifting letters or words from one line into another
3 : to flow over the river overran its banks


over·​run | \ ˈō-vər-ˌrən , ˈō-və-\

Definition of overrun (Entry 2 of 2)

1 : an act or instance of overrunning especially : an exceeding of the costs estimated in a contract for development and manufacture of new equipment
2 : the amount by which something overruns
3 : a run in excess of the quantity ordered by a customer

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Synonyms for overrun

Synonyms: Verb

foray (into), invade, raid

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Examples of overrun in a Sentence


The tank divisions overran the countryside. The city was being overrun by enemy troops. The plane overran the runway. His speech overran the time allowed.
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Recent Examples on the Web: Verb

For example, Democrats keep talking about how far away the caravan of would-be migrants is, rather than simply affirming that several thousand people ought not to overrun the borders of the United States. James Freeman, WSJ, "Americans Aren’t Just Happy about the Economy," 5 Nov. 2018 In 1973, just six years earlier, Israel had barely stopped a surprise attack by Arab air and ground forces that threatened to overrun the country. Kyle Mizokami, Popular Mechanics, "Sheep Glands Point to Nukes as Source of Mysterious 1979 Explosion," 12 Sep. 2018 With Hitler’s invading armies poised to overrun Moscow, Soviet leader (and erstwhile bank robber) Joseph Stalin ordered key personnel to evacuate the capital. Tim Folger, Discover Magazine, "Chance Encounters," 17 Aug. 2018 Kabul is overrun with mafia-style networks that control the national drug trade and bring violence to the streets with armed robberies and factional warfare. Javid Ahmad, WSJ, "The Mafia That Threatens Afghanistan," 19 Sep. 2018 On weekends, the place is overrun by fun-hungry tourist types and causeway crawlers. Rene Rodriguez, miamiherald, "Think South Beach is crazy now? Here's what the club scene was like in 1994 | Miami Herald," 5 May 2018 The toxic algae bloom has overrun Florida’s southern Gulf Coast this summer, devastating sea life and driving people from the water. Tamara Lush, The Seattle Times, "In first 8 months of year, manatee death toll surpasses 2017," 20 Aug. 2018 But what’s happening at the border is the border is being overrun by those who have no right to cross it. BostonGlobe.com, "Here’s how Homeland Security’s Kirstjen Nielsen defended the controversial separation immigration policy," 18 June 2018 The insurgents have not overrun any other city, a fact that U.S. military officials often point to as a sign of fatal weakness. Pamela Constable, chicagotribune.com, "Taliban overrun parts of Afghan city of Farah in major offensive," 15 May 2018

Recent Examples on the Web: Noun

Recent American and European efforts to build first-of-a-kind reactor designs in a hyper-regulated environment have led to large cost overruns and delays. Joshua S. Goldstein And, WSJ, "Only Nuclear Energy Can Save the Planet," 11 Jan. 2019 However, given the difficulties involved in building the KC-46, including long delays and cost overruns, a brand new tanker could be postponed into the 2040s. Kyle Mizokami, Popular Mechanics, "The KC-135 Tanker Could Become the First U.S. Warplane To Serve 100 Years," 31 Dec. 2018 The $20 billion bridge took almost a decade to build while incurring major delays and cost overruns. Dake Kang, The Seattle Times, "China opens mega-bridge linking Hong Kong to mainland," 23 Oct. 2018 Fourth, in order to secure Turkey’s cooperation, the Kurdish question needs a better answer—one that addresses Ankara’s security concerns while also preventing Kurdish positions in Syria’s north from being overrun. Ryan Crocker And, WSJ, "After the Syria Strike, a Strategy," 15 Apr. 2018 The wooden model costs $16.95 — unless, of course, there are overruns. Fredrick Kunkle, Washington Post, "Metro is hawking swag when what people really want is a safe, reliable commute," 6 Mar. 2018 Any direct-imaging telescope projects are going to cost billions of dollars to launch, and that may be difficult for Congress to swallow, especially given the delays and cost overruns of JWST. Loren Grush, The Verge, "The search for alien life needs a new space telescope, astronomers say," 8 Sep. 2018 One example of this is an option available on Airbus aircraft called runway overrun protection. Alyson Behr, Ars Technica, "More than an auto-pilot, AI charts its course in aviation," 5 Dec. 2018 The move resulted in some big cost overruns, including on projects the Air Force tanker program finally awarded to Boeing, forcing contractors to absorb losses or request additional funding when programs ran into problems. Doug Cameron, WSJ, "Defense Companies Battle Over Price," 24 Oct. 2018

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

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First Known Use of overrun


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


1898, in the meaning defined at sense 1

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Statistics for overrun

Last Updated

6 Feb 2019

Look-up Popularity

Time Traveler for overrun

The first known use of overrun was before the 12th century

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More Definitions for overrun



English Language Learners Definition of overrun

 (Entry 1 of 2)

: to enter and be present in (a place) in large numbers
: to run or go beyond or past (something)
: to spread over or throughout (something)



English Language Learners Definition of overrun (Entry 2 of 2)

: an amount of money that is spent and that is more than the expected or planned amount


over·​run | \ ˌō-vər-ˈrən \
overran\ -​ˈran \; overrun; overrunning

Kids Definition of overrun

1 : to take over and occupy by force The outpost was overrun by the enemy.
2 : to run or go past The runner overran second base.
3 : to spread over so as to cover Weeds overran the garden.

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