1. when Hell freezes over - Adverb
2. when Hell freezes over - Phrase
when Hell freezes over (not comparable)
(idiomatic, slang, informal, hyperbolic) Never; not in this lifetime or a time in the unforeseeably distant future; not a chance.
"Will you go out with him?""When Hell freezes over!"
"When will the sun shine in Dunedin?""When Hell freezes over!"
Synonyms: see Thesaurus:never
After almost a decade of magical success, the Eagles broke up in 1980 over clashing personalities and the story goes that Henley commented that the band would play together again “when hell freezes over.” Source: Internet
I’ll buy them both a warm Bud Light when hell freezes over. Source: Internet