in Roman antiquity, a feast or ceremony instituted by Tarquinius Superbus, in honour of Jupiter Latiaris or Latialis.—Tarquin having made a treaty of alliance with the Latins, proposed, in order for perpetuating it, to erect a common temple, where all the allies, the Romans, Latins, Hernici, Volsci, &c. should assemble themselves every year, hold a kind of fair, exchange merchandises, feast, sacrifice, and make merry together. Such was the institution of the Latiar. The founder only appointed one day for this feast; the first confounded another to it, upon concluding the peace with the Latins; and a third was added after the people who had retired to the Mons Sacer were returned to Rome; and a fourth, after appeasing the sedition raised on occasion of the plebeians aspiring to the consuliate.

These four days were called the Latin feriae; and all things done during the course of the feriae, as feasts, sacrifices, offerings, &c. were called Latiares.