Definition of "mistress"

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.

1918, W[illiam] B[abington] Maxwell, chapter XIX, in The Mirror and the Lamp, Indianapolis, Ind.: The Bobbs-Merrill Company

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

2006, Amelia May Kingston, The Triumph of Hope, page 376

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

1711 June 26 (Gregorian calendar), [Joseph Addison; Richard Steele et al.], “FRIDAY, June 15, 1711”, in The Spectator, number 92; republished in Alexander Chalmers, editor, The Spectator; a New Edition, […], volume I, New York, N.Y.: D[aniel] Appleton & Company, 1853

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

1702–1704, Edward [Hyde, 1st] Earl of Clarendon, “(please specify |book=I to XVI)”, in The History of the Rebellion and Civil Wars in England, Begun in the Year 1641. […], Oxford, Oxfordshire: Printed at the Theater, published 1707

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

1815 February 24, [Walter Scott], Guy Mannering; or, The Astrologer. […], volumes (please specify |volume=I to III), Edinburgh: […] James Ballantyne and Co. for Longman, Hurst, Rees, Orme, and Brown, […]; and Archibald Constable and Co., […]

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

c. 1613, Thomas Middleton, William Rowley, “Wit at Several Weapons. A Comedy.”, in Comedies and Tragedies […], London: […] Humphrey Robinson, […], and for Humphrey Moseley […], published 1647, (please specify the act number in uppercase Roman numerals, and the scene number in lowercase Roman numerals)

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.

2001, Paul Hemenway Altrocchi, Most Greatly Lived

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

2013, Andrea Khalil, North African Cinema in a Global Context: Through the Lens of Diaspora

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

1905, Samuel Rutherford Crockett, Maid Margaret of Galloway