The Collaborative International Dictionary of English v.0.48:

Electro-dynamic \E*lec`tro-dy*nam"ic\, Electro-dynamical
\E*lec`tro-dy*nam"ic*al\, a. (Physics)
   Pertaining to the movements or force of electric or galvanic
   currents; dependent on electric force.
   [1913 Webster]