后門
?back door (or gate)
?back-door (or backstairs)influence
走～get in by the “back door”；get sth done through pull; make a back-door (or undercounter) deal/走～之風practice of back--door deals/前門 拒狼，～進虎drive the wolf away from the front door and let a tiger in at the back—fend off one danger only to fall prey to another