c. 1300, "female teacher, governess; supervisor of novices in a convent," from Old French maistresse "mistress (lover); housekeeper; governess, female teacher" (Modern French maîtresse), fem. of maistre "master," from Latin magister "chief, head, director, teacher" (see master (n.)).
Sense of "a woman who employs others or has authority over a household and servants" is from early 15c. Meaning "woman who has mastered an art or branch of study" is from mid-15c. Sense of "kept woman of a married man" is from early 15c. As a polite form of address to a woman, mid-15c. Meaning "woman who is beloved and courted, one who has command over a lover's heart" is from c. 1500.
1580s, abbreviation of mistress (q.v.), originally in all uses of that word. Prefixed to the name of a married woman by 1610s. The plural Mmes. is an abbreviation of French mesdames, plural of madame, used in English to serve as the plural of Mrs., which is lacking. Pronunciation "missis" was considered vulgar at least into 18c. (compare missus). The Mrs. "one's wife" is from 1920.
"the term of honour to a young girl" [Johnson], originally (17c.) a shortened form of mistress (compare Mrs., pronounced mis-ez). By 1640s as "prostitute, concubine." By 1700 as "a young, unmarried woman."
Misses as a trade term (originally in the mail order business) for sizes or styles of clothes for girls from about 10 to 17 years old is by 1880. Miss America is from 1922 as the title bestowed on the winner of an annual nationwide U.S. beauty/talent contest. Earlier it meant "young American women generally" or "the United States personified as a young woman," and it also was the name of a fast motor boat. In the 1811 reprint of the slang dictionary, Miss Laycock is given as an underworld euphemism for "the monosyllable."
It forms all or part of: acromegaly; Almagest; Charlemagne; maestro; magisterial; magistral; magistrate; Magna Carta; magnate; magnitude; magnum; magnanimity; magnanimous; magni-; Magnificat; magnificence; magnificent; magnify; magniloquence; magniloquent; Magnus; maharajah; maharishi; mahatma; Mahayana; Maia; majesty; major; major-domo; majority; majuscule; master; maxim; maximum; may (v.2) "to take part in May Day festivities;" May; mayor; mega-; megalo-; mickle; Mister; mistral; mistress; much; omega.
It is the hypothetical source of/evidence for its existence is provided by: Armenian mets "great;" Sanskrit mahat- "great, mazah- "greatness;" Avestan mazant- "great;" Hittite mekkish "great, large;" Greek megas "great, large;" Latin magnus "great, large, much, abundant," major "greater," maximus "greatest;" Middle Irish mag, maignech "great, large;" Middle Welsh meith "long, great."
"sweetheart," 1748, from the name of Don Quixote's mistress in Cervantes' romance, the name is a Spanish fem. derivative of Latin dulce "sweet" (see dulcet).
1845, "mistress of a castle or household," from French châtelaine "a female castellan; wife of a castellan; mistress of a castle or country house;" fem. of châtelain, from Old French chastelain "owner and lord of a castle, nobleman; keeper of a castle" (Modern French châtelaine), from chastel "castle," from Latin castellum "castle" (see castle (n.)). In fashion, as a type of ornamental belt, from 1851; it is supposed to resemble a chain of keys such as a chatelaine would wear.