Source : Webster's Revised Unabridged Dictionary (1913)

Sumatran \Su*ma"tran\, a.
   Of or pertaining to Sumatra or its inhabitants. -- n. A
   native of Sumatra.

Source : WordNet®

Sumatran
     adj : of or relating to the island of Sumatra or its inhabitants;
           "Sumatran cigars"
     n : a native or inhabitant of Sumatra