An Etymological Dictionary of the German Language/Annotated/Schwelle

by Friedrich Kluge

Schwelle, feminine, ‘threshold, sill,’ from Middle High German swęlle, feminine and neuter, ‘beam, threshold.’ Old High German swęlli, masculine, ‘threshold’; Gothic *swalli, ‘threshold,’ is wanting. Compare Anglo-Saxon syll, feminine, English sill, and the equivalent Old Icelandic syll, svill, feminine; allied to Gothic ga-suljan, ‘to establish,’ root swol, sū̆l, ‘to establish’; con Latin solea (for *svolea)?. Akin also to Old High German sûl, ‘pillar’?.