off like a dirty shirt

Adjective

humorous not-comparable slang

(slang, humorous, simile) Going away; taking one's departure.

Japanese Meaning

（俗語、ユーモラスな比喩）さっと立ち去る、急に去ることを意味する表現

As soon as the fireworks ended, the crowd was off like a dirty shirt, streaming out of the park.

花火が終わると、観客はさっさと立ち去り、公園からどっと出て行った。

Sense（1）

(slang, humorous, simile) Going away; taking one's departure.