Declining rhymes with:
reclining, reclining, aligning, lining, realigning, reclining, affining, aligning, assigning, breining, brining, combining, confining, defining, designing, dining, divining, fining, lining, mining, opining, pining, realigning, reassigning, reclining, redefining, redesigning, refining, resigning, shining, signing, twining, vanhyning, vining, whining, wining
Declining sounds like:
dazzling, declines, disallowance, disallowances, disallowing, disclaiming, disclaims, duckling, ducklings