munition (n.)

1530s, "fortification, action of fortifying or defending" (a sense now obsolete),  also "materials used in war," from Middle French municion "fortification, defense, defensive wall" (14c.), from Latin munitionem (nominative munitio) "a defending, fortification, protecting," noun of action from past-participle stem of munire "to fortify," from moenia "defensive walls," related to murus "wall" (see mural). Female workers in British shell factories in World War I were called munitionettes.