of or relating to or characteristic of Scotland or its people or culture or its English dialect or Gaelic language
Scots Gaelic. The Scots community in New York. `Scottish' tends to be the more formal term as in `The Scottish Symphony' or `Scottish authors' or `Scottish mountains'. `Scotch' is in disfavor with Scottish people and is used primarily outside Scotland except in such frozen phrases as `Scotch broth' or `Scotch whiskey' or `Scotch plaid'.
source: WordNet 3.0
Of or pertaining to the Scotch; Scotch; Scottish; as, Scots law; a pound Scots (1s. 8d.).