Try Our Apps
NFL Quiz: The Final Four
The angular distance between the prime meridian and another meridian passing through a point on the Earth's surface, having the center of the Earth as its vertex. Compare
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Discover our greatest slideshows
8 Wintry Words
8 Words for Celebration
8 Offbeat Literary Genres to Get...
Decode the pieces of our favorite...
Browse more topics on our blog
What Is the Difference Between Discreet and Discrete?
Learn the correct uses of these two commonly confused homophones.
What Character Was Removed from the Alphabet?
What mistaken pronunciation gave this character its name?
This small mark has two primary uses: to signify possession or omitted letters.
How Do I Get a Word into the Dictionary?
People invent new words all the time, but which ones actually make it?
Word of the Day
Word Value for
Words With Friends
Nearby words for geocentric longitude