Meaning

noun the mistress of a chateau or large country house

noun a chain formerly worn at the waist by women; for carrying a purse or bunch of keys etc.

origin] Borrowed from French châtelaine, the feminine form of châtelain (“castle-keeper, castellan; one living in a castle”), from Medieval Latin castellanus (“occupants of a castle”), from castellum (“castle, fort”) (diminutive of castrum (“castle, fort”), from Proto-Indo-European *ḱes- (“to cut off, separate”)) + -ānus (“of or pertaining to”). By surface analysis, Old French chatel + French -aine.

Etymology from Wiktionary, CC BY-SA 3.0