underworld

n the underworld [sing] 1 (in mythology) place under the earth inhabited by the departed spirits of the dead （神话中的）阴间, 阴曹. 2 part of society that lives by vice and crime 下流社会; 黑社会: police contacts in the London underworld伦敦黑社会中的警方眼线 * [attrib 作定语] leading underworld figures, ie notorious criminals 黑社会的头面人物（劣迹昭彰的罪犯）.

understand, understandable, understandably, understanding, understate, understated, understatement, understood, understudy, undertake, undertaker, undertaking, undertone, undertow, underutilize, undervalue, underwater, underwear, underweight, underwent, underwrite, underwriter, undeserved, undeservedly, undeserving, undesignated, undesirable, undesirably, undetectable, undeterred, undeveloped, undid, undies, undignified, undirected, undischarged, undisclosed, undiscovered, undisputed, undistinguished,