Decaying rhymes with:
allaying, arraying, baying, betraying, buffeting, conveying, crocheting, delaying, dismaying, disobeying, displaying, doomsaying, fraying, graying, greying, haying, heying, laying, nonpaying, obeying, overplaying, paying, playing, portraying, praying, prepaying, preying, purveying, repaying, replaying, saying, slaying, spraying, staying, straying, surveying, swaying, weighing
Decaying sounds like:
dagenais, dascenzo, dashing, datsun's, dawkins, dawson's, deaconess, deacons, deakins, decency, decision's, decisions, decking, deigning, deigns, dejong, dejonge, dejongh, dekoning, descenza, deschenes, deshong, designees, designing, designs, deskins, des_moines, diagnose, diagnoses, diagnosis, diasonic, diasonics, dicenso, dicenzo, dicing, dickens, dickens', dickens's, diegans, diesing, digangi, digging, diggins, dioxins, discenza, discussing, discussions, disengage, disguising, dishing, dishong, dishwashing, dismaying, dismays, dismiss, dismisses, dismuke, dismukes, disney's, dissing, dissonance, ditching, dixon's, dixons, dizziness, dizzying, docking, dockings, dockins, dodging, dogging, dosing, dougans, dougens, douggins, dousing, dowsing, dozens, dozing, ducking, dudzinski, duesing, duggins, duking, duquesne's, dusing, duszynski, dwiggins