Brass

Brass meaning money dates from the 16th century. (See also Where there’s muck, there’s brass). Because of its association as a cheap imitator of gold, brass also means effrontery or impudence. This meaning is also from the 16th century and gave rise to the adjective brassy meaning cheap or common. Shakespeare speaks of “brassy bosoms” in Merchant of Venice (c. 1598) Act IV, Scene I, “from brassy bosoms and rough hearts of flint”. Hence, the expression, “bold as brass” which means boldness that borders on rudeness or effrontery and dates from the 18th century.