septic tank

American  

[sep-tik tangk] / ˈsɛp tɪk ˌtæŋk /

noun

1. a tank, often underground, in which organic sewage is decomposed and purified by anaerobic bacteria.

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septic tank British  

noun

1. a tank, usually below ground, for containing sewage to be decomposed by anaerobic bacteria

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Etymology

Origin of septic tank

First recorded in 1900–05

Example Sentences

See Examples For:

septic tank

At one point, the cave faced a potential threat when someone attempted to develop the land and convert the cave into a septic tank.

From Science Daily ● Apr. 3, 2026

Her bathroom became a toilet she fastened on top of her septic tank outside and exposed for her neighbors to see — had any of them come back.

From Los Angeles Times ● Sep. 30, 2025

There were six beds arranged in three bunk beds, and in one corner there was a septic tank and "a pipe that served as a shower".

From BBC ● Jan. 8, 2025

During one of our conversations, Carter choked up when he told of completing a house for a woman and her family who had been living in an abandoned septic tank.

From Los Angeles Times ● Dec. 29, 2024

And Sophie still treated me as if I’d crawled in from the septic tank.

From "Schooled" by Gordon Korman

Related Words

• cesspool
• sewer