Specifically, in electricity, periodicaliy reversing or changing the direction in such a manner that the total effect in one direction is the same as in the opposite direction.

verb. Present participle of alternate.

adjective. that alternates

adjective. Having a planar diagram whose crossings alternate between "over" and "under" as one travels along the knot.

adjective. Having terms that alternate between positive and negative.

adjective. (of a current) reversing direction

adjective. occurring by turns; first one and then the other

"Now featured below, their poem "Apple Jack Tangles the Maidy Lac with a Red, Red Ribbon" was written in alternating voices."

alternating group  alternating motion  alternating symmetry  

cyclic  cyclical  

alternating current  

alternate