ef·flu·ent
ˈe-ˌflü-ənt 
e-ˈflü-,
ə-
: 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
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
Noun
The factory has been accused of discharging effluent into the river.
Recent Examples on the Web
Caroline Fraser
june 10, Literary Hub, 10 June 2025
The Midwest plant received satisfactory results in most areas, including receiving waters; effluent/discharge; permit; stormwater; facility/site; operation; maintenance; sludge; flow measurement; laboratory; records/reports; and enforcement.
—Maya Wilkins, Chicago Tribune, 28 May 2025
James Rainey, Los Angeles Times, 11 May 2025
According to the World Bank, toxic effluents from dyes and finishing agents contain carcinogens and heavy metals such as chromium, cadmium, lead, arsenic and mercury, contaminating drinking water sources, destroying aquatic ecosystems, and poisoning farmland.
—Dianne Plummer, Forbes.com, 18 Apr. 2025
See All Example Sentences for effluent
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Adjective
Soon the waste and effluent and slag heaps are strewn beside the bay and across the Tacoma tidal flats like offal dropped from a raptor’s nest.
—Caroline Fraser
june 10, Literary Hub, 10 June 2025
The Midwest plant received satisfactory results in most areas, including receiving waters; effluent/discharge; permit; stormwater; facility/site; operation; maintenance; sludge; flow measurement; laboratory; records/reports; and enforcement.
—Maya Wilkins, Chicago Tribune, 28 May 2025
Noun
But many questions remain: Where would the effluent from a PCH sewer be treated?
—James Rainey, Los Angeles Times, 11 May 2025
According to the World Bank, toxic effluents from dyes and finishing agents contain carcinogens and heavy metals such as chromium, cadmium, lead, arsenic and mercury, contaminating drinking water sources, destroying aquatic ecosystems, and poisoning farmland.
—Dianne Plummer, Forbes.com, 18 Apr. 2025
See All Example Sentences for effluent
Cite this Entry
“Effluent.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/effluent. Accessed 18 Jun. 2025.
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