23 skidoo (sometimes 23 skiddoo) is an American slang phrase generally referring to leaving quickly, being forced to leave quickly by someone else, or taking advantage of a propitious opportunity to leave. Popularized during the early 20th century, the exact origin of the phrase is uncertain. 23 skidoo has been described as "perhaps the first truly national fad expression and one of the most popular fad expressions to appear in the U.S", to the extent that "Pennants and arm-bands at shore resorts, parks, and county fairs bore either [23] or the word 'Skiddoo'." "23 skidoo" combines two earlier expressions, "twenty-three" (1899) and "skidoo" (1901), both of which, independently and separately, referred to leaving, being kicked out, or the end of something. "23 skidoo" quickly became a popular catchphrase after its appearance in early 1906. Origin Although there are a number of stories suggesting the possible origin of the phrase, none has been universally accepted. Flatiron Building Perhaps the most widely known story of the origin of the expression concerns the area around the triangular-shaped Flatiron Building at Madison Square in New York City. The building is located on 23rd Street at the intersection of Fifth Avenue and Broadway, the latter two of which intersect at an acute angle. Because of the shape of the building, winds swirl around it. During the early 1900s, groups of men reportedly gathered to watch women walking by have their skirts blown up, revealing legs, which were seldom seen publicly at that time. Local constables, when sometimes telling such groups of men to leave the area, were said to be "giving them the 23 Skidoo". An early nickelodeon film, What Happened on Twenty-third Street, which dates from 1901, shows a woman's skirt being lifted by the updraft from a ventilation grate, exposing her knees. Some consider the Flatiron Building origin claim dubious because the slang expressions "23" and "skidoo" were already in use before 1902, the year in which the Flatiron Building was built. "23" (or "Twenty-Three") The earliest-known report of the slang expression "23" (or "twenty-three") as a code word for asking someone to leave is a newspaper reference on March 17, 1899: At the time, a stage version of A Tale of Two Cities, The Only Way, was playing in London. The production moved to New York City later that year; it opened at the Herald Square Theatre on September 16, 1899. Less