a. The natural phenomenon of attraction between physical objects with mass or energy; the weakest of the four fundamental forces of nature. Also called gravity.
b. The act or process of moving under the influence of this attraction.
c. See gravitational interaction.
2. A movement toward a source of attraction: the gravitation of the middle classes to the suburbs.
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.