Opining rhymes with:
pining, affining, aligning, assigning, breining, brining, combining, confining, declining, defining, designing, dining, divining, fining, lining, mining, pining, realigning, reassigning, reclining, redefining, redesigning, refining, resigning, shining, signing, twining, vanhyning, vining, whining, wining
Opining sounds like:
obeying, obnoxious, offense, offenses, offing, opening, openings, openness, opens, openshaw, opines, opinions, oppens, ovens, ovonic