From 'bath' (Old English 'bæþ,' possibly from PIE *bʰeh₁-, to warm) + 'room' — literally 'the warming room.'
A room containing a bath or shower and typically also a washbasin and toilet.
A compound of 'bath' + 'room.' 'Bath' comes from Old English 'bæþ' (a bath, act of bathing, quantity of water for bathing), from Proto-Germanic *baþą (bath), possibly from PIE *bʰeh₁- (to warm) — making a bath literally 'a warming.' Some scholars connect it instead to a root meaning 'to soak' or link it to Latin 'fovēre' (to warm, cherish). 'Room' comes from Old English 'rūm' (space, extent, scope), from Proto-Germanic *rūmą (spacious area), from PIE *rewh₁- (open space), which also produced Latin 'rūs' (countryside, open
'Bath' may come from PIE *bʰeh₁- (to warm) — bathing was understood as warming, not cleaning. The city of Bath in England is named for its hot springs. 'Baden' in German place names (Baden-Baden, Wiesbaden) means 'bathing' from the same root. And 'spa' comes from the Belgian town of Spa