a. One regarded as the initial source of energy directed toward a goal: Patriotism was the prime mover of the revolution.
b. The initial force, such as electricity, wind, or gravity, that engages or moves a machine.
c. A machine or mechanism that converts natural energy into work. Also called primum mobile.
2. Any of various heavy-duty trucks or tractors.
3. Philosophy In Aristotelian philosophy, an eternal, immaterial being of pure motion that cannot be changed but is the cause of change and motion.
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.