gunmetal

1. (historical) A type of bronze used for making cannons.Examples: "The beſt Guns are not made of malleable Metal, and cannot be made of pure Copper or Braß; but it is neceſſary to put in courſer Metals to make it run cloſer and ſounder, as Lead and Pot-metal. […] About 20l. of Lead is uſually put into 100l. of Pot-metal; but about 6l. is ſufficient to put into 100l. of Gun-metal."; "Braſs, Copper, Latten, Bell-Metal, Pan-Metal, Gun-Metal, or Shruff-Metal, whether clean or mixed, carried beyond Sea, forfeits double the Value thereof; (Tin and Lead only excepted) the Informer half, […]"; "Phosphorus is known to improve the strength of copper, and to make it cast soundly. Abel, chemist to the British War Department, stated before the Institute of Civil Engineers, that he had made some experiments upon the combinations of phosphorus and copper, and "had found that by the introduction of a small proportion, say from 2 to 4 per cent., of phosphorus into copper, a metal was produced remarkable for its density and tenacity, and superior in every respect to ordinary gun-metal. […] The experiments alluded to were merely preliminary, and had been, to a certain extent, checked by the improvements since introduced in the construction of field-guns, which had led to a discontinuance of the employment of gun-metal.""countablehistoricaluncountable

2. (also attributive) A dark grey or bluish-grey colour; gunmetal grey.Examples: "Yet even asleep, a Sabre, Jaguar, Harrier, Phantom, Falcon or Eagle holds the eye as a design classic, and that worrisome beauty is still there close up—the cared for, nurtured, spoiled feel, the expensive finish, the quality of the materials, the craftsmanship evident in the flush rivets, the highly polished canopy, the gunmetal sheen of the external instrument sensors, each carefully protected by rubber sheaths with flapping red tags to remind the pilot to take them off before flight."alsoattributivecountableuncountable