1 [C] [usu.sing] an impact (on/upon sb/sth) an effect or impression 影响;印象:
I hope this anti-smoking campaign will make/have an impact on young people.我希望这场反吸烟运动能对年轻人产生影响。
2 [U] the action or force of one object hitting another 撞击:
The impact of the crash threw the passengers out of their seats.这下撞击的冲力把乘客抛离了座位。The bomb exploded on impact.炸弹受到碰撞就马上爆炸了。