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1620s, from French soldiers' faulty separation of Middle French la munition into l'ammunition; from Latin munitionem (nominative munitio) "a fortifying" (see munition), and at first meaning all military supplies in general. The mistake in the word perhaps was by influence of French a(d)monition "warning." The error was corrected in French (Modern French munition), but retained in English.
: The fat ammo barge rocked up and downnoun
the projectiles and propelling charges used in small arms, artillery, and other guns. Ammunition size is usually expressed in terms of calibre, which is the diameter of the projectile as measured in millimetres or inches. In general, projectiles less than 20 mm or .60 inch in diameter are classified as small-arm, and larger calibres are considered artillery. A complete round of ammunition consists of all the components necessary for one firing of the gun. These normally include a projectile, the propellant, and a primer that ignites the propellant. Other components such as cartridge case, fuze, and bursting charge are frequently included.