effluent

1 of 2

adjective

ef·​flu·​ent ˈe-ˌflü-ənt 

e-ˈflü-, 

ə-

: flowing out : emanating, outgoing

an effluent river

effluent

2 of 2

noun

: 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

Adjective

The effluent treatment plant (ETP) is running. —Céline Van De Loo, Sourcing Journal, 16 Dec. 2025

Jun and Arthur finish their effluent business by the time J finishes his own. —Literary Hub, 15 Aug. 2025

Noun

Triarchy says the technology reduces water use by over 90 percent, eliminates toxic effluents, shortens production timelines and cuts costs. —Angela Velasquez, Sourcing Journal, 5 Mar. 2026

Sewage is put in at one end, works its way through the system and comes out at the other end as a nutrient-dense effluent with the toxins filtered out. —Keith Cooper, Space.com, 3 Mar. 2026

Word History

Etymology

Adjective

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

First Known Use

Adjective

1726, in the meaning defined above

Noun

1859, in the meaning defined above

Kids Definition

effluent

noun

ef·​flu·​ent

ˈef-ˌlü-ənt;

e-ˈflü-, 

ə-

: liquid (as sewage or industrial by-products) discharged as waste

effluent adjective