A mickey is an alcoholic drink that’s been altered to incapacitate the person who drinks it.
It’s become a very dangerous idea, especially for young women, but it started out innocently enough in a Chicago bar owned by a man named Mickey Finn.
Around the turn of the twentieth century, Finn discovered that he could get rid of an obnoxious customer by slipping a diarrheic into his drink.
Within minutes the troublesome drinker would have urgently left the bar.