Diptychs; tablets of wood, metal, or other substance, used among the Romans for the purpose of writing, and folded like a book of two leaves. The diptychs of antiquity were especially employed for public registers. They were used in tht Greek, and afterwards in the Roman, church, as registers of the names of those for whom supplication was to be made, and are ranked among the earliest monastic records. BurrilL
DIPTYCHA
TheLaw.com Law Dictionary & Black's Law Dictionary 2nd Ed.