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

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

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

Initially, the fire agency reported that the woman fell into a sinkhole, but later clarified that the hole was in fact an old septic tank that was no longer in use.

From Los Angeles Times • Feb. 8, 2024

Just as the sink drains out, flush a nearby toilet to try to force all the water into the sewer or your septic tank.

From Seattle Times • Nov. 27, 2023

We did our summons after dark, at a twenty-foot-long pit in front of the septic tank.

From "The Battle of the Labyrinth" by Rick Riordan

Related Words

• cesspool
• sewer