calcium cyanide

noun

: a compound Ca(CN)₂ that gives off hydrogen cyanide on exposure to air, is made usually in impure black or gray flakes, powder, or cast blocks by heating crude calcium cyanamide in the presence of salt in an electric furnace, and is used chiefly as an insecticide and rodenticide and in making hydrogen cyanide and ferrocyanides

called also black cyanide

Word History

First Known Use

circa 1893, in the meaning defined above

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