1) Change by reversal 2) Reverse 3) Turn 
[v] - reverse the direction of (an alternating electric current) each half cycle so as to produce a unidirectional current
verb reverse the direction of (an alternating electric current) each half cycle so as to produce a unidirectional current
to reverse the direction of (a current or currents), as by a commutator. · to convert (alternating current) into direct current by use of a commutator.