VERB
（鉸接卡車失控時）彎成V字形，彎折
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.
他的車彎成V字形，撞進了反方向車道，車身擋住了所有的3個車道。