grenade (grĬnād´), small bomb either thrown by hand or shot from a modified rifle or a grenade launcher. It may be filled with gas or chemicals but more often holds an explosive charge that fractures the casing into lethal fragments. Grenades were in use as early as the 15th cent., and men trained to use them were called grenadiers. As the grenade fell into disfavor, however, the name grenadier was applied to members of various elite guards, such as those of Frederick II of Prussia and Napoleon I. Grenades were later reintroduced in warfare and have been widely used in the wars of the 20th and 21st cent. The deployment of the XM25 grenade launcher by U.S. forces in 2010 marked the first use of smart technology in small arms; it uses a laser rangefinder and programmable ammunition to determine and set the distance at which the grenade explodes. The rocket-propelled grenade (RPG) uses a launcher to fire a small rocket mounted with a warhead, and is used against armored vehicles.