mid-15c., kyse, coysy, of uncertain origin, possibly from a Scandinavian source, such as Old Norse kveisa "boil," perhaps influenced by Anglo-French queisier, from Old French coisier "to wound, hurt, make uneasy," which seems to be from the same Germanic root as kveisa. But the history is obscure and evidences of development are wanting. Related: Queasily; queasiness.