Uniqueness rhymes with:
bleakness, preakness, weakness, blackness, bleakness, darkness, frankness, harkness, hawkiness, homesickness, likeness, preakness, quickness, sickness, slackness, thickness, weakness
Uniqueness sounds like:
unassuming, unceasing, unconscious, uneasiness, uneconomic, unionizing, unisons, unknowing, unknowns, unsung