VERB
（铰接卡车失控时）弯成V字形，弯折
If a truck that is in two parts jack-knifes, the back part swings around at a sharp angle to the front part in an uncontrolled way as the truck is moving.
例句
His vehicle jack-knifed, and crashed across all three lanes of the opposite carriageway.
他的车弯成V字形，撞进了反方向车道，车身挡住了所有的3个车道。