Fiag or Fiodhaig, a rivulet in Lairg parish, Sutherland, issuing from Loch Fiodhaig (1½ mile x 5½ furl.; 650 feet), and running 5⁵/8. miles southward to Loch Shin (270 feet), at a point 5½ miles ESE of that lake's head. It traverses a glen called from it Glen Fiodhaig, and abounds in capital trout, with a few salmon.—Ord. Sur., sh. 108, 1880.

(F.H. Groome, Ordnance Gazetteer of Scotland (1882-4); © 2004 Gazetteer for Scotland)