An Etymological Dictionary of the German Language/Annotated/empor
empor, adverb, ‘upwards, aloft,’ from Middle High German enbor, enbore, adverb, ‘into or in the heights’; Old High German inbore, in bore, with the same meaning; a combination of the preposition in with the dative of Old High German and Middle High German dor, ‘upper space’ (Old High German also ‘summit’), the origin of which is obscure. It scarcely belongs to the root ber, ‘to carry’ (in Bahre); more probably to empören. The p of the Modern High German word is based on an early Modern High German medium form entbôr, from which entpor, empor, must have been produced.