mistress

noun

1. A woman, specifically one with great control, authority or ownership.

   “She was the mistress of the estate-mansion, and owned the horses.”

   “At the far end of the houses the head gardener stood waiting for his mistress, and he gave her strips of bass to tie up her nosegay. This she did slowly and laboriously, with knuckly old fingers that shook.”

2. A female head of household.
3. A female teacher.

   “games mistress”

4. The other woman in an extramarital relationship, generally including sexual relations.
5. A dominatrix.

   “As part of BDSM play they can enhance the domineering tread of a mistress or hobble the steps of a slave.”

6. A woman well skilled in anything, or having the mastery over it.

   “A letter desires all young wives to make themselves mistresses of Wingate's Arithmetic.”

7. A woman regarded with love and devotion; a sweetheart.

   “he could not forbear putting his horse out of the way , and rode with his mistress behind him round about it”

8. (Scotland)A married woman; a wife.

   “Several of the neighbouring mistresses […] had assembled to witness the event of this memorable evening.”

9. (archaic)A respectful mode of address to a woman.
10. (obsolete)The jack in the game of bowls.

    “Faith, keep a bachelor still, and go to bowls, sir, Follow your mistress there, and prick and save, sir; For other mistresses will make you a slave, sir”

    “She took a bowl, drew up her skirt with her left hand, and rolled the weighted ball with a deft motion. It lightly kissed the mistress and stopped a few inches away.”

11. A female companion to a master (a man with control, authority or ownership).
12. (feminine, form-of)Female equivalent of master.
13. (feminine, form-of)Female equivalent of mister.
14. (archaic)Used as the title of a married woman before her name. Now used only in the abbreviated form Mrs.

    “The sound of Mistress Affery cautiously chaining the door before she opened it, caused them both to look that way.”

    “Mistress Cordelia Carfax shivered and gathered her silk shawl about her shoulders. […] Any shows of affection Mistress Carfax did display were usually reserved for her pedigree pug.”

15. Used as the title of a female dominant.

verb

1. (rare, transitive)Of a woman: to master; to learn or develop to a high degree of proficiency.

   “These films give a glimpse of women on the way to mistressing their own destiny.”

2. (intransitive)To act or take the role of a mistress.

   “[…] housewifery, maternity, charity, the life conventual, the chatter of a court, the mistressing of a great house […]”