An Etymological Dictionary of the German Language/Annotated/ober

by Friedrich Kluge

ober (1.), comparative, ‘upper, higher,’ from Middle High German obere, Old High German obaro, ‘the superior’; properly the comparative of ob. From this was formed, even in Old High German, a new superlative obarôst (Middle High German oberest).

ober (2.), preposition, ‘over, above, beyond,’ of Middle German and Low German origin, as is indicated by the stem vowel, for the o which prevails in Middle German and Low German obar, oƀar, Anglo-Saxon ofer, English over, and the equivalent Dutch over, is always represented in High German by u. See über and auf.