心怀叵测xīn huái pǒ cècherish (/have/nurse)evil intentions; harbour dark (malicious) designs;have some dirty trick up one’s sleeve; one’s motives(/designs) are unfathomable (/unknown);untrustworthy
❍ 近来有几个～的名人间接忠告我，说我去年作文，专和几个人闹意见，不再论及文学艺术，天下国家，是可惜的。(鲁迅《华盖集续编》136)I have recently been indirectly warned by certain prominent citizens whose motives are unknown that it is a pity I kept on attacking people last year in my writings instead of discussing literature and art,the world and China.
❍ 她首先让慈安太后相信了那些顾命大臣～，图谋不轨，然后又获得慈安的同意，秘密传信给恭亲王，招他来热河离宫商议对策。(爱新觉罗·溥仪《我的前半生》4) First she persuaded Ci An that the eight regents were untrustworthy conspirators and then she got Ci An’s consent to a secret letter being sent to Prince Gong summoning him to the palace in Rehe to discuss how to deal with them. 心怀叵测xīn huái pǒ cè叵：不可。形容心里藏着难以猜测的阴谋诡计。have evil intentions, harbour sinister designs, cherish evil designs |