Pronunciation: (mis'tris),[key] —n. 1. a woman who has authority, control, or power, esp. the female head of a household, institution, or other establishment.
2. a woman employing, or in authority over, servants or attendants.
3. a female owner of an animal, or formerly, a slave.
4. a woman who has the power of controlling or disposing of something at her own pleasure: mistress of a great fortune. 5. (sometimes cap.) something regarded as feminine that has control or supremacy: Great Britain, the mistress of the seas. 6. a women who is skilled in something, as an occupation or art.
7. a woman who has a continuing, extramarital sexual relationship with one man, esp. a man who, in return for an exclusive and continuing liaison, provides her with financial support.
8. Brit.a female schoolteacher; schoolmistress.
9. (cap.) a term of address in former use and corresponding to Mrs., Miss, or Ms.