[Agent-n. from L. commūtāre.] He who or that which commutes or exchanges. spec. A contrivance in an electric machine or telegraph instrument for altering the direction or course of the electric current.
1839. Grove, Contrib. Sc., in Corr. Phys. Forces, 253. A commutator might be easily arranged … for effecting the alternation.
1881. Q. Rev., 446. The commutator … used in all direct current machines … was invented in Italy in 1860.
