peritoneum

noun

peri·​to·​ne·​um ˌper-ə-tə-ˈnē-əm 

plural peritoneums ˌper-ə-tə-ˈnē-əmz  or peritonea ˌper-ə-tə-ˈnē-ə 

: the smooth transparent serous membrane that lines the cavity of the abdomen of a mammal and is folded inward over the abdominal and pelvic viscera

peritoneal

ˌper-ə-tə-ˈnē-əl 

adjective

peritoneally

ˌper-ə-tə-ˈnē-ə-lē 

adverb

Examples of peritoneum in a Sentence

Recent Examples on the Web

Normally this causes fever and abdominal pain that is initially felt in the region around the belly button but then moves to the right lower quadrant as the infection and inflammation spread to the highly sensitive lining of the abdominal cavity known as the peritoneum. —Lisa Sanders, M.d., New York Times, 10 Jan. 2024

Peritoneal dialysis uses the peritoneum, the lining of the abdomen, which contains the organs, to mimic a kidney by using large amounts of fluid inside the peritoneum to absorb wastes without needing to remove the blood from the body. —Dr. Keith Roach, oregonlive, 9 Feb. 2022

What’s under it is the same as what’s under the skin of the rest of your abdomen: your abdominal muscles, to which the navel is attached by a short umbilical stalk, and the peritoneum, the membrane that lines the abdominal cavity. —Sarah Leupen, The Conversation, 5 Apr. 2023

What else – my peritoneum, that’s gone. —The Indianapolis Star, 14 Mar. 2023

The hematoma was half the size of a grapefruit and was contained only by a thin, fragile layer of tissue called the peritoneum. —W Roy Smythe, Discover Magazine, 7 Apr. 2014

Using the peritoneum in gender confirmation surgery was popularized by Dr. Lee Zhao at New York University in recent years, and Dr. Kamol is one of the few surgeons in the world performing PPT. —Mailee Osten-Tan, Longreads, 8 June 2022

There are potential complications of peritoneal dialysis, including infection of the peritoneum. —Dr. Keith Roach, oregonlive, 9 Feb. 2022

This then would result in the inflammation of your peritoneum, the lining of the insides of your abdomen, called peritonitis, which can be a life-threatening condition and is a surgical emergency. —Bruce Y. Lee, Forbes, 31 Jan. 2022

Word History

Etymology

Middle English, from Late Latin, from Greek peritonaion, neuter of peritonaios stretched around, from peri- + teinein to stretch — more at thin

First Known Use

15th century, in the meaning defined above

Kids Definition

peritoneum

noun

peri·​to·​ne·​um ˌper-ət-ᵊn-ˈē-əm 

plural peritoneums or peritonea

-ˈnē-ə

: the smooth transparent membrane that lines the cavity of the abdomen and encloses the abdominal and pelvic organs

Medical Definition

peritoneum

noun

peri·​to·​ne·​um

variants or chiefly British peritonaeum

ˌper-ət-ᵊn-ˈē-əm 

plural peritoneums or chiefly British peritonaeums -ˈē-əmz  or peritonea or chiefly British peritonaea -ˈē-ə 

: the smooth transparent serous membrane that lines the cavity of the abdomen of a mammal, is folded inward over the abdominal and pelvic viscera, and consists of an outer layer closely adherent to the walls of the abdomen and an inner layer that folds to invest the viscera see parietal peritoneum, visceral peritoneum compare mesentery sense 1