Lewis & Short

Celtae, ārum, m., = Κελταί,

  1. I. a great parent-stock of people in the north of Europe, the Celts; among the Romans, in a more restricted sense, the inhabitants of Middle Gaul, Caes. B. G. 1, 1; Liv. 5, 34, 1; Mel. 3, 2, 4; cf. Plin. 4, 17, 31, § 105 sq.
  2. II. Hence deriv.: Celtĭcus, a, um, adj.
    1. A. Celtic, of Middle Gaul: Gallia, Plin. 4, 17 31, § 105: spolia, id. 8, 3, 3, § 6.
      * Adv.: Celtĭcē, in the Celtic language, Plin. 33, 3, 12, § 40; Sulp. Sev. Dial. 1, 27.
    2. B. (Acc. to the wide signif. of the Greeks.) Celtĭci, ōrum, m., a people in interior Spain and on the river Guadiana, Mel. 3, 1, 8; 3, 6, 2; Plin. 4, 20, 34, § 111; also adj.: Celtica gens, Mel. 3, 1, 9; and Promonturium, in Gallœcia, now Capo Finisterre, id. 3, 1, 7; Plin. 4, 20, 34, § 111.
    3. C. (In a broader sense.) Celtic = of Upper Italy: rura, Sil. 1, 46.
    4. D. Celtĭca, ae, f. (sc. terra), the Celtic country, Plin. 3, 1, 3, § 14; 6, 13, 14, § 34.
    5. E. Celtĭcum, i, n. (sc. nomen or imperium), the Celtic nation, Celts, Liv. 5, 34, 1.