The underworld in a city is the organized crime there and the people who are involved in it.
例句
...a Spanish Harlem underworld of gangs, drugs and violence...充斥著犯罪團(tuán)伙、毒品和暴力的西班牙哈萊姆區(qū)黑社會(huì)Some claim that she still has connections to the criminal underworld.有人稱(chēng)她仍與黑社會(huì)犯罪勢(shì)力有來(lái)往。
N-SING
地獄；陰間；冥府
In many ancient religions and legends, the underworld is a place under the earth's surface where people go after they die.
例句
...Persephone, goddess of the underworld.冥后珀耳塞福涅
英漢詞典釋義
n.
下流社會(huì);黑社會(huì)
The central character of the novel is a sort of underworld figure.這部小說(shuō)的中心角色是個(gè)黑社會(huì)人物。