U-turn
noun [ C ] uk/ˈjuː.tɜːn/ us/-tɝːn/ (informal U-ie, uk/ˈjuːi/ us)
U 型转弯，180度转弯
a turn made by a car in order to go back in the direction from which it has come
It is illegal to do/make a U-turn on a motorway. 在高速路上掉头是违章的。
mainly disapproving（观念或行为上的）彻底转变
a complete change from one opinion or plan of action to an opposite one
The prime minister did/made a quick U-turn in response to all the adverse publicity. 面对所有这些不利宣传，首相的态度来了个180度的大转弯。