Definition of: Guelf

(gwelf) noun
1. A member of a medieval political faction in Italy that supported the papacy in its struggle against the influence of the German emperors: opposed to the Ghibellines.
2. A member of a German princely family, founded in the time of Charlemagne by Welf I in Swabia, from which the Hanoverian line of English kings descended. Also Guelph. [<Ital. Guelfo, ult. after OHG Welf, a family name]
—Guelf′i·an, Guelf′ic adjective
—Guelf′ism noun