noun, plural un·der·bel·lies.

the lower abdomen; posterior ventral area, as of an animal's body.
the lower surface of an object; underside: the underbelly of an airplane.
a vulnerable area; weak point: an attack on the soft underbelly of Europe.
a dark, seamy, often hidden area or side: a police officer continually exposed to the underbelly of society.

Origin of underbelly

First recorded in 1600–10; under- + belly
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for underbelly

Contemporary Examples of underbelly

Historical Examples of underbelly

  • Goode was peering at the ivory inlay on the underbelly of the stock.

    Murder in the Gunroom

    Henry Beam Piper

  • The scout ship responded like a nervous horse and fluttered away as the rocket burned and arced beneath the underbelly.

British Dictionary definitions for underbelly


noun plural -lies

the part of an animal's belly nearest to the ground
a vulnerable or unprotected part, aspect, or region
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for underbelly

c.1600, from under + belly (n.). In figurative sense of "most vulnerable part" it is recorded from Churchill's 1942 speech. Sometimes used erroneously in sense of "seamy or sordid part" of anything.

Online Etymology Dictionary, © 2010 Douglas Harper