jackknife /ˈdʒækˌnaɪf/ ( jackknifing, jackknifed, jackknifes )

• 1. 

  V-I If a truck that is in two parts jackknifes, the back part swings around at a sharp angle to the front part in an uncontrolled way as the truck is moving. (两截的卡车失控时形成)弯折

  例：

  Traffic on the Pacific Highway near Yatala was delayed early yesterday after a semi-trailer jackknifed and left the road.

  昨天早些时候在太平洋高速公路靠近亚塔拉的地方，一辆半挂卡车弯折并冲出道路后，交通发生了堵塞。