nounprō-mātertĕraPRO-MATERTERA☆ KeepMeaninga great-grandmother's sisterLewis & Short 1879ModernAs printed, 1879PROMATERTERALEWIS & SHORTPROMATERTERAprō-mātertĕra, ae, f., I. a great-grandmother's sister, great-grandaunt, Dig. 38, 10, 1; 10.Read the whole entry