Definition of permafrost
: a permanently frozen layer at variable depth below the surface in frigid regions of a planet (such as earth)
Test Your Vocabulary
Name That Food
-
- Name these cookies!

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
Share permafrost
Time Traveler for permafrost
The first known use of permafrost was in 1943
See more words from the same year