A Mickey Finn is a drug that someone secretly puts into a drink in order to render the drinker unconscious. This is slipping someone a Mickey Finn, related phrases are slip someone a Mickey Finn, slips someone a Mickey Finn and slipped someone a Mickey Finn. Obviously, slipping someone a Mickey Finn is a severe crime. The phrase seems to have originated sometime in the 1890s, taken from the name of a bartender at the Lone Star Saloon and Palm Garden in Chicago at the turn of the last century. His establishment was of low repute, and reportedly he slipped Mickey Finns into customers’ drinks in order to rob them. The existence of this particular bartender seems to be proven by an article in the Chicago Daily News in 1903. Whether this was actually the man’s legal name is up for debate.
A mickey is an abbreviation for the Mickey Finn, the two terms are interchangeable. Note that the term mickey is not capitalized, while the term Mickey Finn is capitalized.
Examples
“He said his older brother was very upset and thought he’d been drugged, that someone had given him a Mickey Finn.” (The San Antonio Express-News)
She was drugged with what was then known as a ‘Mickey Finn’ and could be Rohypnol and woke up on the man’s living room floor to find him having sex with her. (The Daily Mail)
When Louie’s replacement, Charley (Jordan Sidfield), suggests that Louie can succeed at wooing May by giving Alex a Mickey Finn, Blor gets distracted and forgets which drink is intended for Alex. (The Huffington Post)
Some dame had slipped me a mickey and stolen my clothes. (The Washington Post)
“I suppose it’s possible that somebody slipped her a mickey, but that’s not the Marion Jones I know.” (TV Guide)