1911 Encyclopædia Britannica/Chatelaine

CHATELAINE (Fr. châtelaine, the feminine form of châtelain, a keeper of a castle), the mistress of a castle. From the custom of a châtelaine to carry the keys of the castle suspended from her girdle, the word is now applied to the collection of short chains, often worn by ladies, to which are attached various small articles of domestic and toilet use, as keys, penknife, needlecase, scissors, &c.