at the drop of a hat
成語所屬單字hat
at the drop of a hat — 慣用語
1. immediately and without any hesitation, no matter what the situation is.
1.慣用語
釋義
二話不說；毫不猶豫
immediately and without any hesitation, no matter what the situation is.
例句
Vinícius would help a neighbour fix a broken fence at the drop of a hat.
The band is ready to perform at the drop of a hat whenever they are called.