ef·​flu·​ent | \ ˈe-ˌflü-ənt How to pronounce effluent (audio) ; e-ˈflü-, ə-\

Definition of effluent

 (Entry 1 of 2)

: flowing out : emanating, outgoing an effluent river



Definition of effluent (Entry 2 of 2)

: something that flows out: such as
a : an outflowing branch of a main stream or lake
b : waste material (such as smoke, liquid industrial refuse, or sewage) discharged into the environment especially when serving as a pollutant

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Did You Know?

Effluent comes from the Latin verb effluere, "to flow out". In an older meaning, an effluent was a stream flowing out of a river or lake. But nowadays effluent almost always means wastes that pour into our water and air. Liquid factory waste, smoke, and raw sewage can all be called effluents. An effluent filter keeps treated waste flowing out of a septic tank from clogging up its drainage pipes.

Examples of effluent in a Sentence


The factory has been accused of discharging effluent into the river.

Recent Examples on the Web: Adjective

In violation of Kenyan environmental and human rights law, the factory's smelting process would emit fumes, dust, and effluent laden with lead particles, according to a 2015 report by the Ministry of Health. Deborah Bloom, CNN, "The woman risking her life to save a village from lead poisoning," 20 Apr. 2018 This method evaluates the cost of providing recycled water by only including the costs in excess of those incurred for secondary wastewater treatment and borne as a cost of effluent disposal. Julie Gallant, Ramona Sentinel, "Directors raise recycled water rates to reflect cost," 11 Apr. 2018

Recent Examples on the Web: Noun

The finding complicates a long struggle against erosion, sewage effluent, unbridled development, invasive clams and algae to save the lake, 6,225 feet in elevation. Los Angeles Times, "Microplastics are found in Lake Tahoe’s waters for first time ever," 26 Aug. 2019 There are many good reasons to get rid of coal: carbon emissions, particulate pollution, mining effluents, etc. Akshat Rathi, Quartz India, "Stop using India’s coal power plants as an excuse for climate inaction," 18 July 2019 Major cities along the Mississippi watershed also discharge sanitation effluent into tributaries and the main river. WSJ, "Polluting the Mississippi River and the Gulf," 11 July 2019 The water district seeks the extra acreage in part because its agreement with Spangler Peak Ranch to dispose of 100 acre feet of plant effluent as recycled water expires Sept. 31. Julie Gallant, Ramona Sentinel, "Water district eyes eminent domain for sprayfields," 20 June 2019 Starting around midnight Tuesday, experts with the Delaware Department of Natural Resources and U.S. Food and Drug Administration began dyeing the effluent processed at the Kent County Wastewater Treatment Plant a crimson color to track its path. USA TODAY, "Pride pickup, sphinx on move, Tony Stark’s cabin: News from around our 50 states," 13 June 2019 These stains had the look of overflowing effluent, rotted in the sun and impervious to power washing. Spencer Kornhaber, The Atlantic, "The Star Wars Park Is a Space-Junk Fantasy," 5 June 2019 The most serious infractions revealed in the audit include plants that exceed the volume and quality of fish-processing effluent discharged to open water allowed under the permits. Anchorage Daily News, "Audit finds 70 percent of British Columbia fish-processing plants do not comply with environmental regulations," 8 July 2018 Years of poorly controlled antibiotic use in humans and animals, combined with effluent from the local drug industry that turned lakes and streams into breeding grounds for resistance, has left India with few weapons to fight infection. Ari Altstedter, Bloomberg.com, "The Startups Waging War Against Superbugs," 25 June 2018

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


1726, in the meaning defined above


1859, in the meaning defined above

History and Etymology for effluent


Latin effluent-, effluens, present participle of effluere to flow out, from ex- + fluere to flow — more at fluid

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Time Traveler for effluent

The first known use of effluent was in 1726

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More Definitions for effluent



English Language Learners Definition of effluent

formal : liquid (such as sewage or industrial chemicals) that is released as waste

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More from Merriam-Webster on effluent

Rhyming Dictionary: Words that rhyme with effluent

Spanish Central: Translation of effluent

Nglish: Translation of effluent for Spanish Speakers

Britannica English: Translation of effluent for Arabic Speakers

Britannica.com: Encyclopedia article about effluent

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