Let me try this:

would you object to

"a sine wave which (net) results in a current that only flows in one
direction"

if you buy that, would you then accept it to be partially condensed
into:

"a sine wave which (net) results in a non-polarity-alternating current"

if you buy that, would you then accept this:

"a sine wave which (net) results in a direct current"

and then

"a (net) direct current sine wave"