underbelly
/ˈʌndəˌbelɪ/noun
(pl. -ies)
1- the soft underside or abdomen of an animal下腹部。
1.1
- figurative 〈喻〉an area vulnerable to attack弱点; 薄弱环节, 软肋：
these multinationals have a soft underbelly.
这些跨国公司存在一个弱点。
1.2
- figurative 〈喻〉a hidden unpleasant or criminal part of society社会渣滓; 罪犯。