Is it ensure, insure, or assure?
"southern Pacific island and Australia, conceived as a continent," 1849, Modern Latin, from French Océanie (c.1812). Apparently coined by Danish geographer Conrad Malte-Brun (1755-1826). Earlier in English as Oceanica (1832). Oceania was the name of one of the superstates in Orwell's "Nineteen Eighty-Four." Oceanea, name of James Harrington's 17c. ideal state, later was applied to the British empire.