mercy flush

noun

An additional toilet flush to reduce odor or decrease the likelihood of the toilet pipes becoming clogged.

Meanings

nounmercy flush (plural mercy flushes)

plural mercy flushes

  1. slangAn additional toilet flush to reduce odor or decrease the likelihood of the toilet pipes becoming clogged.

    Roni lowered her voice and whispered, "That's Taylor Britt. She's got irritable bowel syndrome that's exacerbated by stress." ¶ "That's nasty. We definitely need a mercy flush."

    2008, Kate Harmon, Sorority 101, New York, N.Y.: Speak, →ISBN, page 97
    3 more examples

    A more usual problem with a hatch is that it was shut too tightly. Rig for dive checks can be done submerged, with sea pressure on the outer hatch. New JOs, doing the check, sometimes forget and shut the outer hatch even more tightly when checking it shut. Subsequently, opening the hatch on the surface can be difficult, even demanding a dive to loosen the hatch. Generally happens only once per career (kinda like a mercy flush over a pressurized sanitary tank).

    1995 October 18, Doug Huffman, “Seawater in submarines”, in sci.military.naval (Usenet)

    For the cruise ship sailors among us; the stool flush ball valve has a three foot long lever positioned at the users elbow. Because of the quantity and quality of submarine food one gets into the habit of "mercy flushes" that are periodic quick pops of the flush valve open and shut (kind'a like with a 1.6 gpf commode).

    1998 April 18, dhuf...@awod.com, “Things S**t-Canned Over the Side ”, in sci.military.naval (Usenet)

    The radiators thumped with steaming water, and a long stream of hissing air sounded miserably through the valves. From one of the stalls came a painful-sounding groan, and someone shouted, "For Christ's sake, give us a fucking mercy flush, would you!"

    2015, Thomas O'Malley, Douglas Graham Purdy, Serpents in the Cold, New York, N.Y. […]: Mulholland Books, →ISBN, page 81
Cite this entry
APA

mercy flush. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/mercy%20flush

MLA

“mercy flush.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/mercy%20flush. Accessed November 4, 2026.

Chicago

WatkinsX Dictionary, s.v. “mercy flush,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/mercy%20flush.

Source: mercy flush on Wiktionary, CC BY-SA 4.0.