“ MISTRESS (adapted from O. Fr. maistresse, mod. maîtresse, the feminine of maistre, maître, master) , a woman who has authority, particularly over a household. As a form of address or term of courtesy the word is used in the same sense as “madam.” It was formerly used indifferently of married or unmarried women, but now, written in the abbreviated form “Mrs” (pronounced “missis”) , it is practically confined to married women and prefixed to the surname; it is frequently retained, however, in the case of spinster cooks or housekeepers, as a title of dignity ”