a. (used with a sing. verb) The branch of mechanics that is concerned with the effects of forces on the motion of a body or system of bodies, especially of forces that do not originate within the system itself. Also called kinetics.
b. (used with a pl. verb) The forces and motions that characterize a system: The dynamics of ocean waves are complex.
2. (used with a pl. verb) The social, intellectual, or moral forces that produce activity and change in a given sphere: The dynamics of international trade have influenced our business decisions on this matter.
3. (used with a pl. verb) Variation in force or intensity, especially in musical sound.
4. (used with a sing. verb) Psychodynamics.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 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.