underbelly

noun

un·​der·​bel·​ly ˈən-dər-ˌbe-lē 

1

: a vulnerable area

also : a corrupt or sordid part

probing the underbelly of the entertainment industry

2

: the underside of a body or mass

Synonyms of underbelly

• underworld

Examples of underbelly in a Sentence

They exposed the underbelly of the nation's economic policy.

the sordid underbelly of city life

Recent Examples on the Web

The new aircraft eschews the Kennedy-era robin's-egg blue exterior of the old plane for a bolder look, with the underbelly of the plane painted navy blue with a red stripe above it. —Arkansas Online, 20 June 2026

The new aircraft eschews the Kennedy-era robin’s egg blue exterior of the old plane for a bolder look, with the underbelly of the plane painted navy blue with a red stripe above it. —Seung Min Kim, Fortune, 20 June 2026

Afterwards, in the stadium’s underbelly, Kaka, Rivaldo and Bebeto mingled with fans. —James Horncastle, New York Times, 20 June 2026

The Irish border is the soft underbelly for a process the British public has long since lost confidence in, as well as in those administering it politically. —Efrat Lachter, FOXNews.com, 9 June 2026

Word History

First Known Use

1942, in the meaning defined at sense 1

Rhymes for underbelly

• vermicelli
• allele
• appellee
• ocelli
• belly
• deli
• jelly
• kellie
• melly
• nellie
• nelly
• shelly

Kids Definition

underbelly

noun

un·​der·​bel·​ly ˈən-dər-ˌbel-ē 

: the underpart of a body or mass

the underbelly of a bomber

also : an area open to attack or damage

the army's underbelly