Origin of iwisMiddle English from Old English gewiss (akin to Ger), certain(ly) from ge-, + wiss, certain: for Indo-European base see wise
Origin of iwisMiddle English from Old English gewis certain ; see weid- in Indo-European roots.
From Middle English iwis, ywis (“certain, sure”), from Old English ġewiss (“certain, sure”), from Proto-Germanic *gawissaz (“known, certain, sure”), from Proto-Indo-European *weyd- (“to know”). Cognate with Dutch gewis (“sure”), German gewiss (“certain”), Danish vis (“sure”). More at wit, wis.