pinchbeck

pinchbeck \PINCH-bek\, noun, adjective:

1. an alloy of zinc and copper used to imitate gold in jewelry-making; by extension, something counterfeit; an imitation
2. not genuine; fake

Watch out for the pinchbeck on the auction site.

We laughed at the pinchbeck heroism in the movie.

by 1734, named for Christopher Pinchbeck (c1670-1732), London watchmaker, who developed the alloy