impulse

1. N-VAR An impulse is a sudden desire to do something. 沖動

Unable to resist the impulse, he glanced at the sea again. 他抑制不住沖動，又看了一眼大海。

2. N-COUNT An impulse is a short electrical signal that is sent along a wire or nerve or through the air, usually as one of a series. 脈沖

It works by sending a series of electrical impulses which are picked up by hi-tech sensors. 它通過傳輸由高技術傳感器收集的電脈沖而起作用。

3. ADJ An impulse buy or impulse purchase is something that you decide to buy when you see it, although you had not planned to buy it. 一時心血來潮的[ADJ n]

The curtains were an impulse buy. 這窗簾是一時心血來潮買下的。

4. PHRASE If you do something on impulse, you suddenly decide to do it, without planning it. 憑一時沖動

Sean's a fast thinker, and he acts on impulse. 肖恩是個思維敏捷、憑一時沖動行事的人。