incubus
n
(pl ~es or -bi )
(a) male evil spirit formerly supposed to have sex with a sleeping woman 梦淫妖(传说与熟睡女子交合的妖魔). Cf 参看 succubus.
(b) (rhet 修辞) thing (eg an approaching examination, an unpaid debt) that oppresses sb like a nightmare 给某人造成巨大压力的事物(似恶梦中所见的可怕事物, 如临近的考试、 未清偿的债务).