Here's what rhymes with ceitfulness.
deceitfulness Words that almost rhyme with ceitfulness
feebleness peacefulness evenness ceaselessness gleefulness covetousness deaconess heedlessness speciousness steaminess vehemence sleeplessness unevenness treasonous dreaminess facetiousness speechlessness cenotaphs creaminess grievousness needlessness recentness edematous ingeniousness egregiousness pediments