at the drop of a hat片语

KK [æt ðə drɑp ʌv ə hæt] /æt ðə dɹɑp ʌv ə hæt/

片语

1
立刻、毫不犹豫地、随时口语
He would quit his job and move abroad at the drop of a hat.
他会毫不犹豫地辞掉工作，搬到国外去。