out like a light

In real, traceable use. Part of the curated seed collection; community review is coming.

Meaning · English

Asleep or unconscious, particularly if this has occurred suddenly and the sleep is deep.

Nghĩa · Tiếng Việt

Ngủ sâu hoặc bất tỉnh, đặc biệt nếu xảy ra đột ngột

Machine-translated — suggest a fix

Register: colloquial

Where it’s used: Used American English

Examples

Once she received anesthesia, she was out like a light.

Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30)

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30 via kaikki.org).

Common questions

What does “out like a light” mean?

Asleep or unconscious, particularly if this has occurred suddenly and the sleep is deep.

Is “out like a light” formal or informal?

out like a light is generally colloquial.