a. Relating to or resulting from the forces that create the structural and deformational features of the earth's lithosphere, especially its continents, oceans, and mountains.
b. Of or relating to a tectonic plate or plates.
a. Relating to construction or building.
3. Of great, often disruptive consequence or significance: tectonic shifts in the industry.
[Late Latin tectonicus, from Greek tektonikos, from tektōn, builder; see teks- in the Appendix of Indo-European roots.]
(click for a larger image)tectonic
tectonic rift where the North American Plate is pulling away from the Eurasian Plate
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 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.