An Etymological Dictionary of the German Language/aus

by Friedrich Kluge

aus, adv. and prep., ‘out, forth, from, by reason of,’ from the equiv. MidHG. and OHG. ûȥ, adv., prep.; corresponds to Goth. ût, adv., ‘out (thither, hence),’ AS. ût, ‘out (thither, hence), out of doors, outside,’ E. out, Du. uit, prep., adv., ‘out,’ OSax. ût. Comp. außen, außer. The common Teut. ût (from ût-a?) is based upon Aryan ûd (ŭd); comp. Sans. ud, a verbal particle, ‘out, out (thither), aloft, upwards.’