"energetic force; motive force," 1894, from dynamic (adj.). As "manner of interaction," by 1978.
by 1812, "pertaining to mechanical forces not in equilibrium, pertaining to force producing motion" (the opposite of static), from French dynamique introduced by German mathematician Gottfried Leibnitz (1646-1716) in 1691 from Greek dynamikos "powerful," from dynamis "power," from dynasthai "to be able, to have power, be strong enough," which is of unknown origin. The figurative sense of "active, potent, effective, energetic" is from 1856 (in Emerson). Related: Dynamically.
powerful explosive consisting of a mixture of nitroglycerine with an absorbent, 1867, from Swedish dynamit, coined 1867 by its inventor, Swedish chemist Alfred Nobel (1833-1896), from Greek dynamis "power" (see dynamic (adj.)) + -ite (2). Figurative sense of "something potentially dangerous" is from 1922. Positive sense of "dynamic and excellent" by mid-1960s, perhaps originally African-American vernacular.