cir·cum·horizontal arc
Definition of circumhorizontal arc
: a colored halo of 90° extent or less that is red on the upper side, parallel to the horizon and 46° or a little more below the sun, and produced by the refraction of light across 90° angles at the undersides of ice crystals in suspension in the air
Test Your Vocabulary
Slippery Words Quiz—Changing with the Times
- What is an earlier meaning of nice?

Test your vocabulary with our 10-question quiz!
TAKE THE QUIZ
Spell words. Make bears.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridgedWords at Play
Ask the Editors
Word Games
Slippery Words Quiz—Changing with the Times
Do you know these earlier meanings of words?
Take the quizWords of Snow and Ice Quiz
A selection of words from the chillier parts of t...
Take the quizHow Strong Is Your Vocabulary?
Test your vocabulary with our 10-question quiz!
Take the quizPlay the game
Share circumhorizontal arc