Lat·in a.
 1. Of or pertaining to Latium, or to the Latins, a people of Latium; Roman; as, the Latin language.
 2. Of, pertaining to, or composed in, the language used by the Romans or Latins; as, a Latin grammar; a Latin composition or idiom.
 Latin Church Eccl. Hist., the Western or Roman Catholic Church, as distinct from the Greek or Eastern Church.
 Latin cross. See Illust. 1 of Cross.
 Latin races, a designation sometimes loosely given to certain nations, esp. the French, Spanish, and Italians, who speak languages principally derived from Latin. Latin Union, an association of states, originally comprising France, Belgium, Switzerland, and Italy, which, in 1865, entered into a monetary agreement, providing for an identity in the weight and fineness of the gold and silver coins of those countries, and for the amounts of each kind of coinage by each. Greece, Servia, Roumania, and Spain subsequently joined the Union.