Where does “smokeroom” come from?

smokeroom (English) comes from English room, from Middle English roum, from Old English rūm, from Proto-West Germanic rūm, from Proto-Germanic rūmaz, from Proto-Indo-European rewh₁- — free space.

Ancestry of “smokeroom”, step by step

smokeroom traces back through two separate lines of ancestry.

via English room

StepLanguageWordMeaning
1EnglishroomOpportunity or scope; Space "for" something, or...
2Middle EnglishroumA space or area; A room
3Old Englishrūmroom, space; roomy, spacious, ample, extensive,...
4Proto-West Germanicrūmroomy, spacious; room, open space
5Proto-Germanicrūmazroomy, spacious, open
6Proto-Indo-Europeanrewh₁-free space

via English smoke

StepLanguageWordMeaning
1EnglishsmokeThe visible vapor/vapour, gases, and fine...
2Middle Englishsmokesmoke
3Old Englishsmocasmoke
4Proto-Germanicsmukôsmoke, nebulous air
5Danishsmug-secretly
Every word from Proto-Indo-European rewh₁-
smokeroom — Etymology, Origin & Word History | Etymology Explorer