back·​flow | \ ˈbak-ˌflō How to pronounce backflow (audio) \

Definition of backflow

: a flowing back or returning especially toward a source

Examples of backflow in a Sentence

Recent Examples on the Web Local insurance agent Ray Sandoval was leery about having let a city Water Works employee inside his office to check his backflow preventer the day before the city’s public announcement. Christian Sheckler, Indianapolis Star, 6 Apr. 2020 Start by closing the valve on the backflow preventer, which is also known as a pressure vacuum breaker. Timothy Dahl, Popular Mechanics, 16 Sep. 2019 Shut the backflow valve and then open the manual drain valve on the sprinkler system. Timothy Dahl, Popular Mechanics, 16 Sep. 2019 Metacarpal When the head is lowered, valves in the veins close to prevent backflow of blood. National Geographic, 20 Sep. 2019 Charcoal and pieces of rock from the ensuing tsunami’s backflow were discovered, although sulfur was notably absent, according to researchers. Fox News, 10 Sep. 2019 County auditors said Moore in a year’s time had made more than $18,000 in questionable purchases, including 11 faucets, 11 backflow-preventer repair kits and 108 feet of red brass pipe that could not be accounted for. Larry Barszewski,, 7 Aug. 2019 Calcium deposits in heart valves lead to scarring that can restrict outflow and allow backflow. WSJ, 8 Oct. 2018 Keep in mind that some kits don’t include pressure regulators, timers, backflow preventers, and line filters. The Editors, Good Housekeeping, 17 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'backflow.' 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 backflow

1878, in the meaning defined above

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The first known use of backflow was in 1878

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Cite this Entry

“Backflow.” Dictionary, Merriam-Webster, Accessed 23 Jun. 2021.

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