一時・１時|いちじichiji[2]nakadaka (mid-high)

1. nounone o'clock
   誰だれかから電話でんわがあったら一いち時じに戻もどるといって下ください。↗

   If anyone should phone, say I will be back at one o'clock.
2. adverb, nounonce; at one time; formerly; before
   彼かれは一時いちじここに住すんでいた。↗

   He lived here for a time.
3. adverb, no-adjectivefor a time; for a while; for the time being; for the moment; temporarilyin weather forecasts, indicates that a given condition will hold for less than one quarter of the forecast period
   霧きりのために、交通こうつうは一時いちじ不通ふつうになっている。↗

   Due to the fog, traffic is temporarily suspended.
4. noun (prefix)a time; one time; once

• Related短時間たんじかんNeutral「短時間」 is a short length of time, as in 「短時間で終わる」; it describes duration objectively, while 「一時」 also means 'for the time being' or 'at one time'.
• Related一刻いっこくNeutral「一刻」 is a moment, often in 「一刻も早く」 or 「一刻を争う」, stressing urgency; 「一時」 centers on 'for a time' and 'once'.
• Relatedつかの間つかのまNeutral「つかの間」 is a very brief span of time, as in 「つかの間の休息」, with a literary flavor; 「一時」 also covers 'for a time' and 'once'.
• Related寸時すんじWritten「寸時」 is a written word for a brief moment, as in 「寸時を惜しむ」; shorter than 「一時」 and rare in everyday speech.
• Related寸秒すんびょうWritten「寸秒」 is a written word for an extremely short instant, seen in 「寸秒を争う」; it stresses how brief the time is.
• Related分秒ふんびょうNeutral「分秒」 means every minute and second, typically in 「分秒を争う」, conveying that there is no time to lose.
• Related寸刻すんこくWritten「寸刻」 is a written word for a moment, synonymous with 「寸時」; it is seldom used in modern Japanese.
• Antonym恒常こうじょうWritten「恒常」 is a written word for a constant, unchanging state, the opposite of the temporary 「一時」.
• Antonym永続えいぞくWritten「永続」 refers to something continuing for a long time, the opposite of 「一時」, which lasts only a while.

Use 「一時」 for one o'clock, 'for a time' or 'at one time'. For a simply short duration pick 「短時間」; for time pressure, 「一刻」 or 「分秒」; for a fleeting moment, 「つかの間」.

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

1. （いちじ）時刻じこくの名な。零れい時じの次つぎ、二に時じの前まえ。
2. （いちじ、いっとき、ひととき）ある短みじかい時間じかん。特とくに過去かこのある期間きかん。
3. （いちじ）一回いちかい。
4. （いちじ、いちどき、いっとき）同時どうじ。
5. （いっとき、ひととき）昔むかしの時間じかん区分くぶん。現在げんざいの二に時間じかん。
6. （いちじ）ある現象げんしょうが連続的れんぞくてきに起おこり、発現はつげん期間きかんが予報よほう期間きかんの1/4未満みまんであること。