Word Origin & History
brass
O.E. bræs, originally an alloy of copper and tin (now bronze), in modern use an alloy of two parts copper, one part zinc. A mystery word, with no known cognates beyond Eng. Perhaps akin to Fr. brasser "to brew," since it is an alloy. It also has been compared to O.Sw. brasa "fire," but no sure connection can be made. The meaning "effrontery, impudence" is from 1624. Slang sense of "high officials" is first recorded 1899. Brassy "debased yet pretentious" is from 1586; in the sense of "strident and artificial" it is from 1865. The brass tacks that you get down to (1897) are probably the ones used to measure cloth on the counter of a dry goods store, suggesting precision.