Lewis & Short

Scōti (Scotti), ōrum, m., the Scots, a people in the northern part of Britain, in the mod. Scotland, Amm. 27, 8, 5; 26, 4, 5; Hier. in Jovin. 2, 7.
In sing.: Scotus, collect., Claud. B. Get. 417; id. IV. Cons. Hon. 33; id. Laud. Stil. 2, 251.
Hence,

  1. A. Scō-tĭa, ae, f., the land of the Scots, = Hibernia, Isid. 14, 6, 6.
  2. B. Scōtĭcus (Scott-), a, um, adj., of or belonging to Scotland, Scottish, Scotch: tela, Claud. Laud. Stil. 2, 254.