1. A substitution, exchange, or interchange.
a. The substitution of one kind of payment for another.
b. The payment substituted.
3. The travel of a commuter.
a. Conversion of alternating to unidirectional current.
b. Reversal of current direction.
5. Law Reduction of a penalty to a less severe one.
[Middle English commutacioun, from Latin commūtātiō, commūtātiōn-, from commūtātus, past participle of commūtāre, to alter, exchange; see COMMUTE.]
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.