The Collaborative International Dictionary of English v.0.48:
Sumatran \Su*ma"tran\, a. Of or pertaining to Sumatra or its inhabitants. -- n. A native of Sumatra. [1913 Webster]WordNet (r) 3.0 (2006):
Sumatran adj 1: of or relating to the island of Sumatra or its inhabitants; "Sumatran cigars" n 1: a native or inhabitant of Sumatra