Ponderous rhymes with:
slanderous, thunderous, murderous, odorous, slanderous, thunderous, adulterous, adventurous, amorous, avarice, barbarous, boisterous, cancerous, cantankerous, carboniferous, carnivorous, coniferous, dangerous, decorous, fossiliferous, generous, glamorous, hatteras, herbivorous, heterosporous, homosporous, humerous, humerus, humorous, insectivorous, lazarus, lecherous, murderous, numerous, obstreperous, odorous, omnivorous, onerous, overgenerous, oviparous, ovoviviparous, phosphorous, phosphorus, precancerous, preposterous, prosperous, rancorous, rapturous, rhinoceros, rigorous, slanderous, sonorous, temerous, tetramerous, thunderous, timorous, traitorous, treacherous, unglamorous, uterus, vigorous, viviparous, vociferous
Ponderous sounds like:
painter's, painters, pandora's, pantera's, panther's, panthers, panthers', penders, pepenadores, pindaric, pointers, ponderosa, ponderosa's, ponders, pounders