In plural, Often, Slang Demerol, especially when used as a recreational drug.
“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:
“Whatchu got, man?” / “Reds, bennies, dexies, yellow jackets, demmies.” / “Yeah, demmies're good shit, man. I pay you. Fuck. I got money. I'm hurting inside. Got beat up. Where my money?”1998, Jeffery Deaver, The Coffin Dancer, New York, NY: Pocket Books, published 2021, →ISBN, page 285:
1 more example
In one of the longest lags between a drug's introduction and a new warning, Demerol, a widely used pain reliever, got a new warning in February 2003: It passes straight into mother's milk, […]. Demerol was introduced in the 1930s. It took 70 years to discover that Demmies pass unaltered into breast milk?2004, Russ Kick, 50 Things You're Not Supposed to Know, volume 2, New York, NY: The Disinformation Company, →ISBN, page unknown:
Let the Demmies rail and shout, / And what is it all about, / When they prate of “tariff and reform?” / By their actions in the past / Well we know from first to last, / What the wonders are that they'd perform.1888, “Hear the Joyful Song”, in The Tippecanoe Campaign Songster: Harrison and Morton; Sketch of Their Lives and Full Text of the Republican Platform, W. F. Shaw Co., page 17:
The cheapness of these so-called “great” men was shown when a Senate committee on Unemployment Insurance elected their chairman. Senator Wagner, a Demmy, presented the motion in the Senate that Unemployment Insurance be probed. He, together with Senators Hebert (R. I.) and Glenn (Ill.) were appointed on the committee in the order named.1931 May, James P. Egan, “Comment on the National Show”, in Machinists' Monthly Journal, volume 43, number 5, Washington, D.C.: International Association of Machinists, page 300: