Gizi is a diminutive of Gizella, itself a Hungarian variant of Giselle. Giselle originates in Germanic languages and means "oath". It was popularized by the Brazilian supermodel Gisele Bundchen. It was also the name of a 10th century Hungarian Queen, as well as the name of a famous French ballet. In the English-speaking countries it has been used as a feminine given name since the 20th century.