abdomen

noun

ab·​do·​men ˈab-də-mən 

-ˌdō-;

əb-ˈdō-mən, 

ab- 

plural abdomens

1

a

: the part of the body between the thorax (see thorax sense 1) and the pelvis with the exception of the back

lesions on the chest and abdomen

… they do away with the need for a waistband, which can cut into your abdomen when you're leaning forwards …

—Liz Dodd

called also belly

b

: the cavity of the abdomen that is lined by peritoneum, is bounded above by the diaphragm, anteriorly by a wall of muscle and tissue, and posteriorly by the spinal column, is continuous below with the pelvic cavity, and contains many of the visceral organs and especially those involved in digestion (such as the stomach, liver, pancreas, kidneys, and intestines) : abdominal cavity

Removal of the gallbladder—a pear-shaped sac in the right side of your abdomen—has little adverse effect on digestion.

—The Mayo Clinic Health Letter

2

: the posterior section of the body behind the thorax (see thorax sense 2) in an arthropod

On a nearby table was a … dish of ants that looked familiar except that they had been feeding on peach nectar and the abdomen of each was a large, swollen, translucent sac.

—The New Yorker

see insect illustration

Synonyms of abdomen

• stomach
• belly

Examples of abdomen in a Sentence

showed us a tiny tattoo on her abdomen, right next to her belly button

Recent Examples on the Web

Other theories suggest that certain cells within the abdomen may transform into endometrial-like tissue, while some evidence points to stem cells or developmental changes that occur before birth. — Daryl Austin, USA Today, 7 July 2026

Laparoscopies are a type of surgery used to diagnose and treat the condition and involve inserting a telescope through an incision in the abdomen, according to the Cleveland Clinic. — Zoey Lyttle, PEOPLE, 7 July 2026

Aji, first diagnosed with pancreatic cancer in 2024 after feeling some unexpected pain in his abdomen, is among a growing group of patients who have experienced the power of this new medication. — Paul Sisson, San Diego Union-Tribune, 6 July 2026

Practice deep abdominal breathing A large portion of the lymphatic system is located in the abdomen, Leprieur explains, so deep abdominal breathing for five minutes a day can help pump lymph throughout your body. — Mélanie Defouilloy, Vogue, 6 July 2026

Word History

Etymology

borrowed from Middle French & Latin; Middle French, borrowed from Latin abdōmen "fat underpart of an animal, belly, paunch," of uncertain origin

Note: Often seen as a derivative of abdere, "to hide, conceal," i.e., "that which is hidden," based on a nominal ablaut form *dhoh₁- from the root *dheh₁- "put." However, Latin abdōmen refers primarily to a body part of animals, and more or less humorously of humans; such usage suggests something prominent rather than something concealed, so the derivation looks somewhat unlikely.

First Known Use

circa 1541, in the meaning defined at sense 1a

Rhymes for abdomen

• cognomen
• bildungsroman
• bowmen
• coman
• foeman
• foemen
• gnomon
• nomen
• omen
• roman
• showman
• showmen

Kids Definition

abdomen

noun

ab·​do·​men ˈab-də-mən 

ab-ˈdō-mən

1

a

: the part of the body between the chest and the hips

b

: the body cavity containing the chief digestive organs

called also abdominal cavity

2

: the hind portion of the body behind the thorax in an arthropod see insect illustration

abdominal

ab-ˈdäm-ən-ᵊl 

-nᵊl

adjective

abdominally

-ē 

adverb

Medical Definition

abdomen

noun

ab·​do·​men ˈab-də-mən, -ˌdō-; əb-ˈdō-mən, ab- 

plural abdomens also abdomina ab-ˈdäm-ən-ə 

1

a

: the part of the body between the thorax and the pelvis with the exception of the back

called also belly

b

: the cavity of the abdomen that is lined by the peritoneum, is bounded above by the diaphragm, anteriorly by a wall of muscle and tissue, and posteriorly by the spinal column, is continuous below with the pelvic cavity, and contains many of the visceral organs and especially those involved in digestion (such as the stomach, liver, pancreas, kidneys, and intestines) : abdominal cavity

2

: the posterior often elongated region of the body behind the thorax in arthropods