Lewis & Short

Lingŏnes, um, m., a people in Celtic Gaul, whence the modern name of their chief city, Langres, Caes. B. G. 1, 26; Plin. 4, 17, 31, § 106.
Afterwards dwelling on the Po, Liv. 5, 35, 2.
Hence,

  1. A. Lingŏ-nĭcus, a, um, adj., Lingonian: bardocucullus, a poor sort of garment worn by the Lingones, Mart. 1, 54, 5: victoria, over the Lingones, Eum. Pan. Const. 6, 3.
  2. B. Lin-gŏnus, i, m., a Lingonian, Mart. 8, 75, 2; Tac. H. 4, 55.