swift and decisive action; rushing through work; rapid speech or writing
A yojijukugo describing something done in one vigorous, uninterrupted sweep—like a river flowing a thousand miles at once. Often used for completing a task quickly, or for fast, fluent talking or writing.
He finished the work in one swift, uninterrupted effort.
彼女のスピーチは一瀉千里の勢いで、聴衆を引きつけた。
Her speech flowed with such rapid momentum that it captivated the audience.