DOUGHBOY. Word that was universally used in the U.S. Army to mean an infantryman, and specifically an American infantryman, up until World War II, when it was replaced with "GI." When it was first used is uncertain, but it can be traced as far back as 1854, when it was already in use on the Texas border, and it was especially popular in World War I. The explanation then was that the infantrymen wore white belts and had to clean them with "dough" made of pipe clay. Originally a term of ridicule used by the mounted service, it was adopted by the infantry itself and used with great pride.
Oliver LymanSpaulding/d. b.
dough·boy / ˈdōˌboi/ • n. 1. a boiled or deep-fried dumpling. 2. inf. a U.S. infantryman, esp. one in World War I.