a. An area of land; ground: climbed a tree to view the surrounding terrain.
b. A particular geographic area; a region: a guide who knows this terrain well.
2. The surface features of an area of land; topography: boots designed for rugged terrain.
3. (also tĕrān) Variant of terrane.
[French, from Old French, from Vulgar Latin *terrānum, alteration of Latin terrēnum, from neuter of terrēnus, of the earth; see TERRENE.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 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.