gun-metal

/G AH1 N M EH1 T AH0 L/
noun
  1. 1

    A type of bronze used for making cannons.

  2. 2

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

  3. 3

    A dark grey or bluish-grey colour; gunmetal grey.

Source: https://en.wiktionary.org/wiki/gun-metal, https://en.wiktionary.org/wiki/gunmetal