lon·gi·tude (lŏnji-td′, -tyd′, lôn-)
1. Angular distance on the earth's surface, measured east or west from the Prime Meridian at Greenwich, England, to the meridian passing through a position, expressed in degrees (or hours), minutes, and seconds.
2. Celestial longitude.
[Middle English, length, a measured length, fromOld French, fromLatinlongitūdō, longitūdin-, fromlongus, long; see del-1 in the Appendix of Indo-European roots.]
(click for a larger image)longitude
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.