\So"len*oid\, n.[Gr. ??? channel + -oid.] (Elec.)
An electrodynamic spiral having the conjuctive wire turned
back along its axis, so as to neutralize that component of
the effect of the current which is due to the length of the
spiral, and reduce the whole effect to that of a series of
equal and parallel circular currents. When traversed by a
current the solenoid exhibits polarity and attraction or
repulsion, like a magnet.