一 斉(いっせい)

いっせい

adverb/no-adjective

all at once, simultaneously

1. all at once, simultaneously

Many things or people doing something at the same time together.

花(はな)が一斉(いっせい)に咲(さ)いた。

The flowers all bloomed at once.

一斉(いっせい)に立(た)ち上(あ)がった。

Everyone stood up at once.

合図(あいず)とともに、選手(せんしゅ)たちが一斉(いっせい)に走(はし)り出(だ)した。

At the signal, the athletes all started running at once.

一斉(いっせい) indicates many people or things acting at the same time. It emphasizes the coordinated, simultaneous nature of the action.

FORMS:

Adverb: 一斉(いっせい)に (all at once)
Modifier: 一斉(いっせい)の + noun (simultaneous ~)

COMMON COLLOCATIONS:

一斉(いっせい)に立(た)ち上(あ)がる: to stand up all at once
一斉(いっせい)検査(けんさ): simultaneous inspection/crackdown
一斉(いっせい)攻撃(こうげき): coordinated attack
一斉(いっせい)送信(そうしん): mass broadcast/transmission
一斉(いっせい)休業(きゅうぎょう): simultaneous closure

SIMILAR WORDS:

同時(どうじ)に: at the same time — neutral, factual
一斉(いっせい)に: all at once — emphasizes coordinated group action
一気(いっき)に: all in one go — emphasizes doing something without stopping

general

Added 2026.1.9 20:57 · Revised 2026.5.17 5:08

01500/01726_issei