Lewis & Short

1. Lār or Lars, Lartis, m., a prænomen of Etruscan origin (in Etruscan, usu: the prefix of the first-born, while a younger son was called Aruns. The name Lar, Lars, or Larth was an honorary appellation in Etruscan, = Engl. lord): Lars Tolumnius, rex Veientium, Cic. Phil. 9, 2; Liv. 4, 17, 1; 4, 58, 7: ad Lartem Porsenam, id. 2, 9 (nom. Lar, Charis. 110 P.).