Definition of zenith eyepiece
: an eyepiece or adapter containing a right-angle prism or a plane mirror to reflect the rays from an object near the zenith to the side of a refracting telescope for more convenient observation
— called also diagonal eyepiece
Test Your Vocabulary
Who Knew?
-
- What is a ruelle?

Test your vocabulary with our 10-question quiz!
TAKE THE QUIZ
A daily challenge for crossword fanatics.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridged
Words at Play
Ask the Editors
Share zenith eyepiece