Words That Rhyme With "Costly" :
2 syllables:
beastly, chastely, christly, crossly, falsie, faulty, frosty, ghastly, ghostly, gristly, hostly, hotly, istle, justly, lastly, moistly, mostly, motley, mottley, potsy, Priestley, priestly, salty, softly, tautly, vastly
3 syllables:
augustly, compressedly, distressedly, professedly, robustly, unjustly