Unaddressed rhymes with:
addressed, addressed, dressed, undressed, abreast, addressed, breast, brest, chrest, compressed, crest, depressed, digressed, distressed, dressed, expressed, impressed, oppressed, pressed, prest, progressed, repressed, rest, stressed, suppressed, transgressed, trest, undressed, unimpressed, unrest, wrest
Unaddressed sounds like:
unauthorized, undercoat, undercooked, undercut, underside, undersized, understate, understated, understood, understudy, underused, underweight, underweighted, undressed, uninterested