A modern spelling of Lacy, originally an English surname from a Norman place-name.
Laci carries a double heritage that gives it an unusual depth for such a breezy-sounding name. In the English-speaking world it arrived as a feminized spelling of Lacey, itself drawn from the Norman French surname de Lacy — a powerful noble family who took their name from Lassy, a commune in Normandy. When the Normans swept into England in 1066, the de Lacys came with them, and the name lodged itself in the landscape of medieval Britain, eventually softening from a surname into a given name favored for girls in the twentieth century.
Meanwhile, in Hungary, Laci functions as a warm, everyday diminutive of László — the Hungarian form of Vladislav, a Slavic name meaning 'glorious rule.' Saint László I, the eleventh-century warrior-king who unified and Christianized the Magyar peoples, made the name a cornerstone of Hungarian identity, and Laci became the affectionate shorthand used by family and friends. Composers, poets, and Olympic athletes named László have been called Laci in their home country for generations.
In contemporary usage the English spelling has drifted fully feminine, often chosen by parents who want something that feels casual and warm without being invented. The double-c variant Lacci occasionally appears, but the single-c form dominates. It sits in an interesting middle ground — rooted enough to feel real, light enough to feel modern — which explains its quiet persistence across very different cultural contexts.