Source : Webster's Revised Unabridged Dictionary (1913)

Celtic \Celt"ic\, a. [L. Celticus, Gr. ?. See {Celt}.]
   Of or pertaining to the Celts; as, Celtic people, tribes,
   literature, tongue. [Written also {Keltic}.]

Celtic \Celt"ic\, n.
   The language of the Celts.

   Note: The remains of the old Celtic language are found in the
         Gaelic, the Erse or Irish the Manx, and the Welsh and
         its cognate dialects Cornish and Bas Breton.

Source : WordNet®

Celtic
     adj : relating to or characteristic of the Celts [syn: {Gaelic}]

Celtic
     n : a branch of the Indo-European languages that (judging from
         inscriptions and place names) was spread widely over
         Europe in the pre-Christian era [syn: {Celtic language}]