a sop to Cerberus
A bribe. Taken from the ancient Greek and Roman custom of leaving gifts with corpses so that Cerberus (guardian of the gates of hell) would pass them by. What is this money, a sop to Cerberus so that I won't tell the authorities what you've done?
a sop to Cerberus
something offered to appease someone. In Greek mythology, Cerberus was the three-headed watchdog which guarded the entrance of Hades. In the Aeneid Virgil describes how the Sibyl guiding Aeneas to the underworld threw a drugged cake to Cerberus, thus enabling the hero to pass the monster in safety.