What is the X in X-mas?
mid-15c., kyse, coysy, of uncertain origin, possibly from a Scandinavian source, cf. 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.
queasy quea·sy or quea·zy (kwē'zē)
adj. quea·si·er or quea·zi·er, quea·si·est or quea·zi·est
Experiencing nausea; nauseated.
Causing nausea; sickening.