An Etymological Dictionary of the German Language/Unbill

by Friedrich Kluge

Unbill, f., ‘iniquity, wrong,’ MidHG. only; based on the cognates of billig, instead of the correct ModHG. Unbilde, f., MidHG. unbilde, n., ‘wrong, impropriety,’ which is properly an abstract from MidHG. (rare) unbil (usually unbillîch), adj., ‘incongruous, unjust.’ On account of the meaning there is probably no direct historic connection with Bild. Comp. billig, and especially Weichbild.