gunmetal

noun3

1. •
   An alloy of 88% copper, 10% tin and 2% zinc, originally used for making guns.

   • It is three tiers high inside the prison and everything is the color of gunmetal. Everything is dark and cold, except for those patches of light, where authority stands. — 1956
2. •
   [before a noun] A dark grey or bluish-grey colour; gunmetal grey.
3. •
   (historical) A type of bronze used for making cannons.