monocle
nounUK /ˈmɒnəkl/
US /ˈmɑːnəkl/
A monocle is a single round glass you wear over one eye to help you see better.
The old gentleman in the story wore a shiny monocle over his right eye.
RELATED WORDS
OTHER MEANINGS
2. A single lens used in a scientific instrument such as a microscope.
The scientist adjusted the monocle on the microscope to see the tiny cells.
3. A small round window or opening shaped like a single lens.
Light came through the little monocle window near the ceiling.
4. A decorative single lens worn as part of a costume.
For the play, she added a fake monocle to look like a fancy detective.