Doughboy was a slang term for American infantrymen, best known from its use in World War I, although it dates back to the Mexican-American War in 1847.

Its etymology is unclear. One theory is that the term comes from the large brass buttons on uniforms that looked like doughnuts, while another is that it derives from the use of pipe clay, which looks like dough, to clean infantrymen’s white belts.

By World War II, the term doughboy had taken on a corny, old-fashioned tone, as in the 1942 song Johnny Doughboy found a Rose in Ireland. It dropped out of popular use, and is now of historic interest only.

For the advertising icon used by the Pillsbury Company, see Pillsbury Doughboy.