Words That Rhyme With "Lessness" :
2 syllables:
baseness, brusqueness, choiceness, crassness, crossness, grossness, gruffness, justness, muchness, niceness, roughness, spruceness, thisness, thusness, toughness
3 syllables:
abstruseness, augustness, conciseness, diffuseness, distressedness, grotesqueness, jocoseness, moroseness, obtuseness, preciseness, profuseness, remissness, robustness, unjustness, verboseness