Origin and history of Don Juan

"man of carnal adventures, connoisseur of seduction," 1888, from Giacomo Girolamo Casanova de Seignalt (1725-1798), the infamous debaucher. His name could be Englished as Jacob Jerome Newhouse, which sounds somewhat less romantic.

masc. proper name, Italian, from Old High German Hlothari, Hludher (whence German Luther, French Lothaire; the Old English equivalent was Hloðhere), literally "famous warrior," from Old High German lut (see loud) + heri "host, army" (see harry (v.)). As a characteristic name for a jaunty rake, 1756, from "the gay Lothario," name of the principal male character in Nicholas Rowe's "The Fair Penitent" (1703).

1737, "pay court to women, especially without serious intent; flirt," from the noun meaning "a lover" (1700), from Philander, popular name for a lover in stories, drama, and poetry, from Greek adjective philandros "with love for people," perhaps mistaken as meaning "a loving man," from phil- "loving" (see philo-) + andr-, stem of anēr "man, male, husband" (see anthropo-). In later 20c. use more sexual than flirtatious. Related: Philandered; philandering.