/ˈɪm.pʌls/
a sudden strong wish or need to do sth, without stopping to think about the results 冲动；心血来潮；一时的念头
He had a sudden impulse to stand up and sing.
他突然心血来潮，想站起来唱歌。
I resisted the impulse to laugh.
我强忍着没有笑出来。
Her first impulse was to run away.
她的第一个念头就是逃走。
The door was open and on (an) impulse she went inside.
门开着，她一时心血来潮就走了进去。
He tends to act on impulse.
他往往凭一时冲动行事。