So last summer, when the Massachusetts State Legislature became one of the first in the nation to consider a bill to add an “X” option for nonbinary genders to the “M” and “F” on the state driver’s license, El, 17, was less surprised than some at the maneuver that effectively killed it. 2019 May 29, Amy Harmon, “Which Box Do You Check? Some States Are Offering a Nonbinary Option”, in The New York Times, archived from the original on 08 Jun 2019:
(abbreviation, alt-of, initialism, not-comparable) Initialism of medium (of the manufactured size).
I also advise reading the Merlin of M Jean Prévost, published by the N. R. F., a swift audacious picture of post-war love, treated with the grace of a Crébillon or of a Restif de la Bretonne. I could not recommend too highly the Petite Histoire des Juifs which MM Jean and Jérôme Tharaud have just published with Plon. 1928 May, Paul Morand, “Paris Letter”, in The Dial, volume LXXXIV, number 6, published June 1928, page 508:
(abbreviation, alt-of, countable, initialism, uncountable) Initialism of men (sign on toilet door).
From the Kierkegaard Room he lopingly careened through a red-carpeted hallway that had previously vouchsafed him a comfort station but this morning seemed all business, no M or W in sight, just salons and boutiques and the Ingmar Bergman Cinema. 2001, Jonathan Franzen, The Corrections, New York, NY: Farrar, Straus and Giroux, →ISBN, page 332:
(abbreviation, alt-of, countable, uncountable) Abbreviation of Monday.
“Anyway, when he came out of Patsy's room, I grabbed him by the arm and said, ‘Gee whiz, doc, haven't you got a couple of pills for me—even demerol?’ ” / Willie broke off to explain. “That's a synthetic. We call them demmies. If you can't buy H or M, why, demmies will do the trick.” 1956, Jess Stearn, Sisters of the Night: The Startling Story of Prostitution in New York Today, New York: Julian Messner, Inc., page 59:
'You were going to get me some M,' she whispered in his ear. […] His friend uses morphine, too. 2009, Larry Harrison, Glimpses of a Floating World, page 142:
That night Marylou took everything in the books; she took tea, goofballs, benny, liquor, and even asked Old Bull for a shot of M, which of course he didn’t give her; he did give her a martini. 1957 September 5, Jack Kerouac, On the Road, New York, N.Y.: Viking Press, →OCLC:
[Doctors] always carry narcotic prescription blanks and some M with them. M is morphine. 1952, Woman's Home Companion, volume 79, page 141:
(countable, in batting figures, uncountable) the number of minutes a player spent at the crease
(countable, in bowling figures, uncountable) the number of maiden overs bowled
(India, Internet, abbreviation, alt-of, countable, initialism, uncountable) Initialism of Muslim; mostly used by Hindutva netizens primarily towards Islamist supporters and Muslim militants.
In all the sexual encounters I have participated in or know of the "M" sets the limits as to what to get into and how much pain will be applied. And of course if the scene gets too rough the "M" has the right to stop it. 1980 April 5, Brian O'Dell, “Sensuality/Mutuality”, in Gay Community News, page 4: