gunmetal , n :
(historical) A type of bronze used for making cannons. An alloy of 88% copper, 10% tin and 2% zinc, originally used for making guns. A dark grey or bluish-grey colour; gunmetal-grey. American gunmaker Eliphalet Remington, who founded the Remington Arms company and designed the Remington rifle, died on this day in 1861.
Source http://handbookblogger.blogspot.com/2017/08/gunmetal-word-of-day-for-august-12-2017.html
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