Source : Webster's Revised Unabridged Dictionary (1913)

Jamaican \Ja*mai"can\, a.
   Of or pertaining to Jamaica. -- n. A native or inhabitant of
   Jamaica.

Source : WordNet®

Jamaican
     adj : of or relating to Jamaica (the island or the country) or to
           its inhabitants; "Jamaican rum"; "the Jamaican Prime
           Minister"

Jamaican
     n : a native or inhabitant of Jamaica