keep ... up one's sleeve

phr

• ① 握有一张尚未亮出来的王牌;有应急计划;胸有成竹
  • Do you have any ideas up your sleeve if our food runs out?如果我们的食物耗尽了,你有什么应急计划?
  • I could see that she had something up her sleeve.我看得出她别有用心[胸有成竹]。