Firenze.

Borrowed from Italian Firenze (“Florence”), from Old Italian Fiorenze (“Florence”), ultimately from Latin Flōrentiae (“at Florence”), the locative of Flōrentia (“Florence”). The change from pretonic fio- to fi- reflects a characteristic Florentine reduction. Forms of the modern type are attested in medieval Tuscany from the mid-thirteenth century, including Firençe (1255), Firenzzie (1287) and Firense (1304). The archaic and literary Italian form Fiorenza (“Florence”) preserves the older initial diphthong. The Latin place name Flōrentia (“Florence”) was formed from flōrēns (“blooming, flourishing”), the present participle of flōreō (“to bloom, flourish”), with the place-name suffix -ia. The verb is related to flōs (“flower”), ultimately from Proto-Indo-European *bʰleh₃- (“to bloom”). The name therefore means roughly “the flourishing city”. Compare Norwegian Nynorsk Firenze and Danish Firenze (“Florence”), likewise based on the Italian endonym. Also compare Swedish Florens, German Florenz, English Florence, French Florence, Spanish Florencia, Portuguese Florença, Polish Florencja, Romanian Florența and Russian Флоренция (Florencija, “Florence”), which continue the same Latin name through other routes.