Also Inflected form of prepay prepaid pre·paid UK/pɹiːˈpeɪd/ US/priˈpeɪd/ uncommon adjective 1. used especially of mail; paid in advance Synonymspostpaid Similarpaid WordNet 2.1 (Princeton University). Wiktionary (CC BY-SA). CMU Pronouncing Dictionary. WordNet 2.1 Copyright Princeton University. All rights reserved.