Of or pertaining to magnetism, the ability to be magnetized or affected by a magnet, or relating to the earth's magnetic field. Magnetism is a class of physical phenomena associated with the motion of charge, the attraction for iron observed in lodestone and a magnet. It is associated with moving electricity, exhibited by electric currents, and characterized by fields of force. It can be an electric current in a conductor or charged particles moving through space, or it can be the motion of an electron in atomic orbit.