一気に|いっきにikkini[1]atamadaka (head-high)

1. adverbin one go; in one gulp; in one breath; without stopping; without pausing; without a rest; in one sitting; at a stretch
   彼かれは一気いっきに１０時間じかん働はたらいた。↗

   He worked ten hours at a stretch.
2. adverbsuddenly; all of a sudden; all at once

• SynonymいっぺんにNeutralDoing everything in one round or all at the same time, as in 「いっぺんに覚えられない」; it stresses the one-shot aspect, while 「一気に」 stresses not stopping midway.
• Synonym一度にいちどにNeutralThings happen or are handled together at the same time, as in 「一度に二つ」; it stresses quantity coming all at once and lacks the one-breath drive of 「一気に」.
• Related一時にいちどきにWrittenAll together at the same time, close to 「一度に」, but rarer and leaning toward written/formal prose; it has none of 「一気に」's sense of going without a break.
• Antonym少しずつすこしずつNeutralGoing forward a little at a time, as in 「少しずつ慣れる」; it is the direct opposite of 「一気に」's finishing in one go.
• Antonym徐々にじょじょにWrittenDescribes slow, gradual change or progress with a slightly written/formal feel; it contrasts with 「一気に」's sudden, all-at-once occurrence.

Use 「一気に」 for doing something in one breath without stopping or happening suddenly, as in 「一気に飲み干す」. Use 「一度に」/「いっぺんに」 for handling everything in one round or all at once; 「一時に」 is a rarer written near-equivalent. For gradual progress, pick 「少しずつ」 or 「徐々に」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 休やすまずに、続つづけて、最後さいごまで一度いちどにやること。
2. 予想よそうしないで、急きゅうに、ぱっと起おこること。