Source : Webster's Revised Unabridged Dictionary (1913)

Tai \Tai\, a.
   Designating, or pertaining to, the chief linguistic stock of
   Indo-China, including the peoples of Siamese and Shan speech.

Tai \Tai\, n.
   A member of one of the tribes of the Tai stock.

         The Tais first appeared in history in Yunnan, and from
         thence they migrated into Upper Burma. The earliest
         swarms appear to have entered that tract about two
         thousand years ago, and were small in number. --Census
                                                  of India,
                                                  1901.

Source : WordNet®

Tai
     adj 1: of or relating to or characteristic of Thailand or its
            people; "Siamese kings"; "different Thai tribes live
            in the north" [syn: {Thai}, {Siamese}]
     2: of or relating to the languages of the Thai people; "Thai
        tones" [syn: {Thai}, {Siamese}]
     3: of or relating to Thailand; "the Thai border with Laos"
        [syn: {Thai}, {Siamese}]

Tai
     n 1: a native or inhabitant of Thailand [syn: {Thai}, {Siamese}]
     2: the most widespread and best known of the Kadai family of
        languages