caveat emptor UK /ˈkeɪ.viˌæt ˈɛmp.tɔ(ɹ)/US /ˈkæv.iˌɑt ˈɛmp.tɔɹ/ phrase2 •Used as a warning to anyone purchasing something that there may be unforeseen problems or faults with the item that is purchased. •(historical) A provision of Roman law which gave the seller of a house the legal right to keep quiet about any defects of the house.