An Etymological Dictionary of the German Language/Annotated/Stube
Stube, feminine, ‘room, chamber,’ from Middle High German stube, Old High German stuba, feminine, ‘room with means for heating, sitting-room, bathroom’; common to Old Teutonic; compare Dutch stoof, ‘foot-stove, drying-room,’ Anglo-Saxon stofa, English stove, Old Icelandic stofa, ‘room, bathroom with a stove.’ Although the Romance origin of the cognates is impossible (Italian stufa, French étuve, ‘sweating-room, stove,’ are certainly borrowed from Teutonic), this does not prove that the words are genuinely Teutonic. The word stuba was adopted in Finnish as tupa, in Lithuanian as stubà; compare Old Slovenian istŭba, izba, Hungarian szoba, Turk. soba, ‘room.’ The primary meaning of the Teutonic word is ‘heated room,’ as may be inferred from Dutch stoven, ‘to stew, warm up’ (whence Italian stufare, French etuver, ‘to foment’).