noun
monocle
MAH-nuh-kul/ˈmɑːnəkl/
A single eyeglass lens worn over one eye.
The monocle covers one eye while the other remains bare.

Etymology
“Single” and “eye” originally formed a description meaning “one-eyed.” That description became the name of an eyeglass serving just one eye.
In context
he screwed his monocle into his eye and bent over the pillow
More examples
- She fits the monocle over her right eye.
- His monocle falls out when he raises his eyebrows.
- The antique shop displays several monocles beside a pair of spectacles.
Forms
monocle · monocles
monocular adjective — Involving or intended for one eye.
Similar words
- eyeglass
- A broader term for a lens used to aid vision.
- glasses
- Usually have two lenses in a frame, covering both eyes.