The Collaborative International Dictionary of English v.0.48:

Turkish \Turk"ish\, pr. a.
   Of or pertaining to Turkey or the Turks. -- n. The language
   spoken by Turks, esp. that of the people of Turkey. --
   Turk"ish*ly, adv. -- Turk"ish*ness, n.
   [1913 Webster]