Source : Webster's Revised Unabridged Dictionary (1913)

Tahitian \Ta*hi"ti*an\, a.
   Of or pertaining to Tahiti, an island in the Pacific Ocean.
   -- n. A native inhabitant of Tahiti.

Source : WordNet®

Tahitian
     adj : of or relating to or characteristic of the island of Tahiti
           or its residents or their language and culture
     n 1: a native or inhabitant of Tahiti
     2: the Oceanic language spoken on Tahiti