The Collaborative International Dictionary of English v.0.48:

Caucasian \Cau*ca"sian\, n.
   1. A native or inhabitant of the Caucasus, esp. a Circassian
      or Georgian.
      [1913 Webster]

   2. A member of any of the white races of mankind.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Caucasian \Cau*ca"sian\, a.
   1. Of or pertaining to the Caucasus, a mountainous region
      between the Black and Caspian seas.
      [1913 Webster]

   2. Of or pertaining to the white races of mankind, of whom
      the people about Mount Caucasus were formerly taken as the
      type.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Caucasian
    adj 1: of or relating to the geographical region of Caucasia;
           "Caucasian languages" [syn: Caucasian, Caucasic]
    2: of or relating to Caucasian people [syn: Caucasian,
       Caucasoid]
    n 1: a member of the Caucasoid race [syn: White, White
         person, Caucasian]
    2: a number of languages spoken in the Caucasus that are
       unrelated to languages spoken elsewhere [syn: Caucasian,
       Caucasian language]