Unending rhymes with:
amending, apprehending, ascending, attending, befriending, bending, blending, commending, comprehending, condescending, contending, defending, depending, descending, ending, expending, extending, fending, impending, intending, lending, mending, misspending, offending, overextending, pending, portending, pretending, recommending, relending, rending, sending, spending, suspending, tending, transcending, trending, unbending, vending, wending
Unending sounds like:
undoing, undying, uniden's, uniting, unwinding, unwitting