ordnancePronunciation: /ˈɔːdnəns/Translate ordnance | into Italian Definition of ordnance noun [mass noun] 1mounted guns; artillery: the gun was a brand new piece of ordnance US munitions: unexploded ordnance 2a branch of government service dealing especially with military stores and materials: [as modifier]:the ordnance corpsOrigin: late Middle English: variant of ordinanceordnance in other Oxford dictionaries Definition of ordnance in the US English dictionary