High Quality Content by WIKIPEDIA articles! Sergeant is a rank used in some form by most militaries, police forces, and other uniformed organizations around the world. Its origins are the Latin serviens, "one who serves", through the French term Sergent. In most armies, the rank of sergeant corresponds to command of a squad (or section). However, in commonwealth armies, it is a more senior rank, corresponding roughly to a platoon second-in-command. In the United States Army, sergeant is a more junior rank, corresponding to a squad second-in-command, and in the United States Marine Corps, a Sergeant is in total command of a squad.