underbelly

Noun

underbelly (plural underbellies)

1. The underside of an animal.
   • We identified the species of the snake by its blue-grey underbelly.
   • The soft underbelly of the dragon. In the legend, the dragon's armor doesn't cover its stomach.1952 September, Philip K[indred] Dick, “The Gun”, in Planet Stories, New York, N.Y.: Love Romances Publishing Company, →OCLC; republished as The Collected Stories of Philip K. Dick, volume 1 (Beyond...
2. The underside of any thing.
   • A jolt told me that the Nautilus had bumped the underbelly of the Ice Bank, still quite thick to judge from the hollowness of the accompanying noise.1993, Jules Verne, chapter 37, in Walter James Miller, Frederick Paul Walter, transl., Jules Verne’s Twenty Thousand Leagues under the Sea: The Definitive Unabridged Edition Based on the Original...
3. (figuratively) The side which is not normally seen, normally a dark, immoral place.
   • The area by the canal is the underbelly of town – not something you’d see in the guidebooks.
   • In order to take the initiative, military leaders from Great Britain and the United States decided to attack in Africa, cross the Mediterranean, and move up against the "soft underbelly" of German-dominated Europe.1967, Boyd C. Shafer, Richard A. McLemore, Everett Auspurger, Kenneth E. Miller, “World Cataclysm and the United States”, in Manual, Test, and Answers for 1865 to the Present: A United States History...