/kow"boy'/ , n.
1. a man who herds and tends cattle on a ranch, esp. in the western U.S., and who traditionally goes about most of his work on horseback.
2. a man who exhibits the skills attributed to such cowboys, esp. in rodeos.
3. Chiefly Northeastern U.S. a reckless or speedy automobile driver.
4. Informal. a reckless or irresponsible person, esp. a show-off or one who undertakes a dangerous or sensitive task heedlessly: They put foreign policy in the hands of cowboys.
5. (during the American Revolution) a member of a pro-British guerrilla band that operated between the American and British lines near New York City.
v.i.
6. to work as a cowboy.
[ 1715-25; COW 1 + BOY ]