An Etymological Dictionary of the German Language/weis
weis, adj., in einem, etwas weis machen, ‘to make one believe, hoax a person,’ from OHG., late MidHG. einen wîs machen, ‘to inform a person, instruct him’ (in ModHG. in an ironical sense). Comp. MidHG. and OHG. wîs tuon, ‘to inform, instruct.’ Allied to weise, adj., ‘wise, prudent, cunning,’ From MidHG. and OHG. wîs (also MidHG. wîse, OHG. wîsi), adj., ‘intelligible, experienced, acquainted with, learned, wise.’ A common Teut. adj.; comp. Goth. weis, ‘knowing,’ OSax. and AS. wîs, ‘wise, knowing,’ E. wise, Du. wijs. The primary form of the word was a verbal adj. from wissen (wîso- for wîtto-). Allied to the following word.