a. Orbital motion about a point, especially as distinguished from axial rotation: the planetary revolution about the sun.
b. A turning or rotational motion about an axis.
c. A single complete cycle of such orbital or axial motion.
2. The overthrow of one government and its replacement with another.
3. A sudden or momentous change in a situation: the revolution in computer technology.
4. Geology A time of major crustal deformation, when folds and faults are formed.
[Middle English revolucioun, from Old French revolution, from Late Latin revolūtiō, revolūtiōn-, from Latin revolūtus, past participle of revolvere, to turn over; see REVOLVE.]
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.