Where did this slang word for woman come from? It comes from a broad being a playing card. This may sound absurd on the face of it, but if you follow the development of slang uses of broad it all becomes clear.
Broad is an 18th century slang term for a playing card, especially one used in three card monte. This usage may refer to style of playing deck. In modern card decks, a bridge deck has narrower cards than are found in a poker deck. If this variation in card size is older (I know words, not cards), then a broad could be a reference to this larger cut of cards. From George Parker’s 1781 A View of Society:
Black-Legs, who live by the Broads and the Turf [...] Cant for cards.
By the 20th century this sense of broad had expanded to include tickets of admission and transportation. From Field’s Watch Yourself of 1912:
Fix the olly! I gave him broads to the show!1
And from Jackson & Hellyer’s 1914 A Vocabulary of Criminal Slang:
“Beating the broads” is corrupting the conductor or other collecting functionaire of a transportation line.2
At about the same time, the term is recorded to mean a prostitute. Also from Jackson & Hellyer:
Broad, Noun Current amongst genteel grafters chiefly. A female confederate; a female companion, a woman of loose morals. Broad is derived from the far-fetched metaphor of "meal ticket," signifying a female provider for a pimp, from the fanciful correspondence of a meal ticket to a railroad or other ticket.3
If the meal ticket connection is too much for you, the sense could have jumped from three card monte to woman. The goal of that game is to pick the queen from among three cards, and broad could have transferred from the card, to the queen, to women.
The general sense of broad meaning a woman, as opposed to the specific one of prostitute, is cited from 1911, from the September issue of Hampton’s Magazine:
Pretty soon what is technically known as a “broad"—"broad" being the latest New Yorkese—hove into sight.
Although this general sense is cited three years earlier than the prostitution sense, it is likely that the prostitution sense is older since the earliest citations of that are in slang dictionaries, meaning the term was around for a while before the lexicographers got hold of it.4
1Historical Dictionary of American Slang, v. 1, A-G, edited by Jonathan Lighter (New York: Random House, 1994), 271.
2Louis E. Jackson and C.R. Hellyer, A Vocabulary of Criminal Slang (Portland, OR: Modern Printing Co., 1914), 20.
3Jackson and Hellyer, Criminal Slang, 19.
4HDAS, v. 1, 271.
Copyright 1997-2015, by David Wilton