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
Literary Hub, 15 Aug. 2025
However, Water and Wastewater Authority of Wilson County Director Chris Leauber says flowing water from the facility is stormwater and that effluent sample readings the wastewater authority has done are a lower number than what the notice says.
—Andy Humbles, The Tennessean, 13 Aug. 2025
Timothy Dale, Better Homes & Gardens, 14 Aug. 2025
Pan said in a statement that menstrual effluent (blood and tissue) shed from the uterus each month is often overlooked as medical waste—and even stigmatized by some—but could help with earlier and more accessible endometriosis detection.
—Health Reporter, MSNBC Newsweek, 24 July 2025
See All Example Sentences for effluent
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Adjective
Jun and Arthur finish their effluent business by the time J finishes his own.
—Literary Hub, 15 Aug. 2025
However, Water and Wastewater Authority of Wilson County Director Chris Leauber says flowing water from the facility is stormwater and that effluent sample readings the wastewater authority has done are a lower number than what the notice says.
—Andy Humbles, The Tennessean, 13 Aug. 2025
Noun
Beneficial bacteria in the tank break down organic waste, while liquid effluent flows out into the drain field for further filtration.
—Timothy Dale, Better Homes & Gardens, 14 Aug. 2025
Pan said in a statement that menstrual effluent (blood and tissue) shed from the uterus each month is often overlooked as medical waste—and even stigmatized by some—but could help with earlier and more accessible endometriosis detection.
—Health Reporter, MSNBC Newsweek, 24 July 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 30 Oct. 2025.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
Share