off like a prom dress

Adjective

Canada US not-comparable slang

(simile, slang, Canada, US) Making a start, or departing, very rapidly.

Japanese Meaning

急いで出発する／始動する / 素早く動き始める / 一気に立ち去る

When the starting gun fired, the runners were off like a prom dress, bolting down the track.

スターティングガンが鳴ると、選手たちは一斉に勢いよくトラックを駆け下り始めた。

Sense（1）

(simile, slang, Canada, US) Making a start, or departing, very rapidly.

When we heard the police car pull up, we were off like a prom dress.