Prepayment rhymes with:
repayment, repayment, copayment, downpayment, nonpayment, payment, repayment, arcement, claimant, copayment, downpayment, embayment, nonpayment, payment, rayment, repayment
Prepayment sounds like:
perfumed, pierpoint, pierpont, pierrepont, prevent, prevented, profanity, profound, proponent, propound, propounded, provant