MISTRESS  (adapted from O . Fr. maistresse, mod. maitresse, the feminine of

maistre, maitre, 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; as the female equivalent of " master " the word is used in other senses by analogy, e.g. of Rome as " the mistress of the world," Venice " the mistress of the Adriatic," &c . From the common use of " master " as a teacher, " mistress " is similarly used . The old usage of the word for a lady-love or sweetheart has degenerated into that of paramour . " Miss " a shortened form of " mistress," is the term of address for a girl or unmarried woman; it is prefixed to the surname in the case of the eldest or only daughter of a family, and to the Christian names in the case of the younger daughters .