| 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 initial capital letter ) 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. | British. a female schoolteacher; schoolmistress. |
| 9. | (initial capital letter ) a term of address in former use and corresponding to Mrs., Miss, or Ms. |
| 10. | Archaic. sweetheart. |