一瞬(いっしゅん)

いっしゅん
noun/adverb
instant, moment, split second
1. instant, moment
An extremely brief period of time.
一瞬(いっしゅん)の出来事(できごと)だった。
It was a momentary event.
一瞬(いっしゅん)目(め)を離(はな)した隙(すき)に。
In the instant I looked away.
一瞬(いっしゅん)で景色(けしき)が変(か)わった。
The scenery changed in an instant.
2. for an instant, momentarily
Used adverbially to describe something happening very briefly.
一瞬(いっしゅん)、何(なに)が起(お)きたか分(わ)からなかった。
For an instant, I didn't understand what happened.
一瞬(いっしゅん)迷(まよ)ったが、すぐに決(き)めた。
I hesitated for a moment, but decided right away.
一瞬(いっしゅん)彼(かれ)の顔(かお)が見(み)えたが、すぐに人込(ひとご)みに消(き)えた。
I caught a glimpse of his face for an instant, but he quickly disappeared into the crowd.

一瞬(いっしゅん) means an extremely brief moment — a split second. It can function as both a noun and an adverb.

COMMON PATTERNS:

  • 一瞬(いっしゅん)の + noun: a momentary ~ (一瞬(いっしゅん)の出来事(できごと): a momentary event)
  • 一瞬(いっしゅん)で: in an instant
  • 一瞬(いっしゅん)にして: in a flash (slightly literary)
  • ほんの一瞬(いっしゅん): just an instant

ADVERBIAL USAGE:
When used adverbially, it often appears at the beginning of a sentence: 一瞬(いっしゅん)、何(なに)が起(お)きたか分(わ)からなかった (For an instant, I didn't know what happened).

SIMILAR WORDS:

  • 瞬間(しゅんかん): moment, instant (often interchangeable, but 瞬間(しゅんかん) can also mean "the moment when")
  • 一刻(いっこく): a moment (literary, often used with 一刻(いっこく)も早(はや)く — as soon as possible)

WORD FORMATION:
一(いっ) (one) + 瞬(しゅん) (blink). Literally "one blink of an eye."

Related Words

Synonym: 瞬間(しゅんかん) (moment, instant)
general
Added 2026.1.9 21:15 · Revised 2026.4.5 16:10
01500/01805_isshun