when Hell freezes over

Proposed by a contributor, not yet supported by evidence.

Meaning · English

when something is extremely unlikely to happen

Nghĩa · Tiếng Việt

Khi điều gì đó cực kỳ khó xảy ra

Machine-translated — suggest a fix

Literally: Hell freezing
Where it’s used: Used Widespread English

Examples

I'll believe it when Hell freezes over

AI-drafted example auto-approved by rule (illustrative, not a corpus attestation)

Sources & notes

Listed in Wiktionary’s “English idioms” category (retrieved 2026-07-29); definition pending editorial review. Definition drafted by AI (@cf/meta/llama-3.3-70b-instruct-fp8-fast) and auto-approved by rule on 2026-07-31; pending editor spot-check.

Common questions

What does “when Hell freezes over” mean?

when something is extremely unlikely to happen Literally: Hell freezing

Is “when Hell freezes over” formal or informal?

No register label has been reviewed yet — treat it as neutral and check the usage notes above.