An Etymological Dictionary of the German Language/Zwetsche
Zwetsche, Quetsche, f., ‘damson’; ModHG. only; a difficult word to explain. Bav. zwèšen, zwèšpen, Swiss zwetške, Austr. zwespen, Thur. and East MidG. quatšge, seem to be related like quer and Zwerch, quängeln and zwingen, so that we must perhaps assume an initial tw. Since damsons were orig. obtained from Damascus (the Crusaders are said to have introduced them into Europe; comp. E. damask plum, damascene, damson, Ital. amascino, Portug. ameixa), it seems probable that the Teut. cognates (Bav. zwèschen) are derived from MidLat. damascena or Gr. δαμάσκηνον through the intermediate forms dmaskîn, dwaskîn, which appear in Transylvanian maschen, mäschen. Yet the phonological relations of the numerous dialectic forms are so indistinct that a final solution of all the difficulties has not yet been found. From HG. are derived Du. kwets, Dan. svedske, Boh. švetska.