Words That Rhyme With "Vastness" :
2 syllables:
ansa's, cantus, chasteness, crassness, daftness, fastness, fatness, flatness, justness, moistness, pastness, patness, Santas, Shasta's, wasteness
3 syllables:
Atlanta's, augustness, discantus, distressedness, downcastness, Erastus, lightfastness, robustness, steadfastness, unjustness