n. spectacles designed to "pinch the nose" (as the term literally means in French), as opposed to eyeglasses held on by sidepieces going over the ears, or opera glasses, which use a handle. The plural is spelt the same, but pronounced with an 's' on the end.*
The pince-nez was made possible by the invention of the steel spring in the mid-19th century. They were unstable and eventually incorporated a cord or ribbon attached on one side to prevent them falling off and shattering, rather like a monocle. Later versions allowed the folding of one lens over the other, for compactness' sake.
The glasses played a central role in Sir Arthur Conan Doyle's short story "The Adventure of the Golden Pince-Nez" published in the 1905 collection "The Return of Sherlock Holmes."
* The words 'corps,' 'rendezvous, 'faux-pas' and 'chassis' do the same.
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