un·der·bel·ly /ˈʌndɚ/
下腹部的,易受攻擊的地帶
underbelly
n 1: lower side; "the underbellies of clouds"
2: the soft belly or underside of an animal's body [syn: underbody]
3: the quality of being weak or unprotected; "the soft
underbelly of the Axis"- Winston Churchill