civ. law. A decree or decision of the Roman senate, which had the force of law. 2. When the Roman people had so increased that there was no place where they could meet, it was found necessary to consult the senate instead of the people, both on public affairs and those which related to individuals. The opinion which was rendered on such an occasion was called senatus consultum. These decrees frequently derived their titles from the names of the consuls or magistrates who proposed them.