一気 いっき
ikkini

Adverb

1. in one go; in one gulp; in one breath; without stopping; without pausing; without a rest; in one sitting; at a stretch

かれ一気 いっき いち れい時間 じかん はたらいた。
karewa ikkini jūjikan hataraita
He worked ten hours at a stretch.
Adverb

2. suddenly; all of a sudden; all at once