(mis′tris) noun
1. A woman in authority or control, or to whom service is rendered; a female head, chief, or owner, as of a country household, an institution, or an estate; also a female schoolteacher.
2. A woman who unlawfully, or without marriage, fills the place of a wife; also, a woman beloved and courted; a sweetheart.
3. A woman who is well skilled in or has mastered anything.
4. Scot. A married woman or wife. [<OF maistresse, fem. of maistre. See MASTER.]

(mis′tris) noun
A title of address formerly applied to both married and unmarried women: now generally supplanted by Mrs. for married and Miss for unmarried women.