卧 wo4 臥
薪 xin1 薪
尝 chang2 嘗
胆 dan3 膽
  1. lit. to sleep on brushwood and taste gall (like King Gou Jian of Yue 勾踐|勾践[Gou1 Jian4]), in order to recall one's humiliations) (idiom)
  2. fig. to maintain one's resolve for revenge

Info