Tasmanian means 'of Tasmania' — the big island that is Australia's southernmost state. It works two ways. As an adjective it describes anything belonging to that island: Tasmanian weather, a Tasmanian farm, Tasmanian wine. As a noun it names a person from there: 'She is a Tasmanian.' By far the most common place a learner meets it is the Tasmanian devil, a small black animal with powerful jaws, a red-eared face and a scream that frightens people at night; it lives wild nowhere else, and the American cartoon character 'Taz' comes from it. You will also see 'Tasmanian tiger' — a striped meat-eating animal, also called the thylacine, that was hunted until none were left, the last one dying in a zoo in 1936; people still argue about whether any survive. The word is also used for the Aboriginal people of the island, and there it needs care, because their history is one of near-destruction by British settlers and the subject is a painful one. Always a capital T, since it comes from a place name. Note that the definition line attached here describes Tasmania, the island itself; this word is the form you use to say that something comes from there.