underworld
noun [ S ] uk/ˈʌn.də.wɜːld/ us/ˈʌn.dɚ.wɝːld/
(CRIME)
黑社会
the part of society consisting of criminal organizations and activities
(IN STORIES)
the underworld （希腊神话中的）阴间，冥府
in mythology, a place under the earth where the spirits of the dead go
Compare: Hades