What does "set off" mean?

To activate an alarm; to begin a journey To trigger something or start traveling.

How do you use "set off" in a sentence?

The smoke set off the alarm. We set off at dawn. Don't set off the security system.

Phrasal Verb BritishAmericanAustralian ★★★★★ Very Common Neutral

Meaning: To activate an alarm; to begin a journey

触发（警报）；出发

Activar (una alarma); partir, salir de viaje

（警報を）作動させる、出発する

경보를 울리다; 출발하다

To trigger something or start traveling.

触发某物或开始旅程。

Disparar algo o comenzar un viaje.

何かを引き起こす、または旅を始める。

무언가를 작동시키거나 여행을 시작하다.

Base verb: set

Particle: off

Separable: Yes — the object can go between the verb and particle

The smoke set off the alarm.
烟雾触发了警报
El humo activó la alarma
煙で警報が鳴った
연기가 경보를 울렸다.
We set off at dawn.
我们黎明时分出发了
Partimos al amanecer
夜明けに出発した
새벽에 출발했다.
Don't set off the security system.
别触发安保系统
No activéis el sistema de seguridad
セキュリティシステムを作動させないで
보안 시스템을 작동시키지 마.

Context: alarms, travel

Tone: action

From triggering or beginning.

Era: Modern

Generation: All ages

Social background: Universal