See dynamics in Webster's New World College Dictionary
noun
the branch of mechanics dealing with the motions of material bodies under the action of given forces; kinetics
the various forces, physical, oral, economic, etc., operating in any field
the way such forces shift or change in relation to one another
the study of such forces
the effect of varying degrees of loudness or softness in the performance of music
See dynamics in American Heritage Dictionary 4
(dī-nămˈĭks)
noun
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.
(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.
(used with a pl. verb) Variation in force or intensity, especially in musical sound.