虎ㄏㄨˇhǔ尾ㄨㄟˇwěi春ㄔㄨㄣchūn冰ㄅㄧㄥbīng

踏到老虎的尾巴，走在春天的薄冰上。比喻處於極端危險的環境。語本《書經·君牙》：「心之憂危，若蹈虎尾，涉于春冰。」反泰山磐石

英lit. like stepping on a tiger's tail or spring ice (idiom), fig. extremely dangerous situation