Gerarai (Ancient Greek: Γεραραί) were priestesses of Dionysus (Bacchus to the Romans) in ancient Greek ritual. They presided over sacrifices and participated in the festivals of Theoinia and Iobaccheia that took place during the month of Anthesteria, among other duties. Fourteen in all, they were either sworn in by the Athenian Basilinna or the Archon Basileus (either the queen or king). One of their primary duties during the Anthesteria was to assist in performing the sacred marriage rites of the queen to Dionysus, and thus held to secrecy. According to a folk etymology, they were called Gerarai, from the Greek word γηράσκω - gerasko "I grow old", because older women were chosen for the role.
Parke, H.W. "Festivals Of The Athenians" Cornell University Press (1990). ISBN 0-8014-9440-0