The more common meaning of the word today, on the rare occasions on which it turns up in print at all, is of something that’s cheap or tawdry. However, those versed in the fields of jewellery, clocks and other objets d’art will know that strictly it refers to an alloy of zinc and copper — so a type of brass — that looks remarkably like gold.
Outside these specialist areas, the word’s most common appearance is as a family name, which is only fit and proper, since we are in the area of eponyms here — things named after people. The man who invented the alloy was one Christopher Pinchbeck, a clockmaker born in Clerkenwell in London, though his shop was at the “sign of the Astronomico-Musical Clock” in Fleet Street. He was also a well-known maker of musical automata such as singing birds. His name probably came from the place called Pinchbeck near Spalding in Lincolnshire; that name is from Old English words meaning either “minnow stream” or “finch ridge” (from which we may deduce the uncertain state of the study of English placenames).
He seems to have invented his eponymous metal sometime in the early 1700s, though there’s no contemporary reference and we have to rely on statements by his sons. He created it as a way to make ornaments that looked like gold but were less expensive. There was no attempt at deception here — he clearly labelled the metal for what it was. To start with, it was a respected alternative to gold: jewellers in the eighteenth century used it legitimately to make nice-looking jewellery that could be worn in places in which theft was frequent, such as on stagecoach journeys, without fear of losing valuables.
However, so many jewellers used it for inferior goods, passing off pinchbeck as gold, that the word took on the sense of something that was of poor quality or a cheap imitation. Nineteenth century authors found in the word a neat metaphor for all that is spurious or counterfeit, as Anthony Trollope did in Framley Parsonage: “Where, in these pinchbeck days, can we hope to find the old agricultural virtue in all its purity?”