impulse
noun uk/ˈɪm.pʌls/ us/ˈɪm.pʌls/
(WISH)
C2 [ C + to infinitive ]冲动，突然的强烈欲望
a sudden strong wish to do something
I had this sudden impulse to shout out "Nonsense!" in the middle of her speech. 在她发言时我突然想大喊“一派胡言！”。
on (an) impulseC2 一时兴起，心血来潮
because you suddenly want to, although you haven't planned to
"I didn't know you were looking for some new shoes." "Oh, I wasn't - I just bought them on impulse." “我不知道你想要买双新鞋。”“噢，不是的——我只是一时冲动才买的。”
(SIGNAL)
[ C ]脉冲
a short electrical, radio, or light signal that carries information or instructions between the parts of a system
an electrical/nerve impulse 电脉冲／神经冲动
(REASON)
[ C usually singular ] formal动机；动力；刺激
something that is the driving force behind or reason for something else
a creative/commercial impulse 创作冲动／商业动机