rictus

noun

1. 扭曲（或怪笑）的嘴；龇牙咧嘴
   a wide twisted or smiling mouth that does not look natural or relaxed

1. As one former banker notes: You just hope everyone's too drunk to notice that your voice is flat and your smile is really a rictus grin.
   正如一位前银行家所言：你就是希望所有人都酩酊大醉，注意不到你那软弱无力的声音和硬挤出来的笑容。
2. His mouth gaping in a kind of rictus of startled alarm ( Richard Adams)
   他的嘴张得有惊跳的闹钟那么大（理查德亚当斯）

noun

1. a gaping grimace