1540s, "of or pertaining to the sea," from Middle French maritime (16c.) or directly from Latin maritimus "of the sea, near the sea," from mare (genitive maris) "sea" (see mere, n.) + Latin ending -timus, originally a superlative suffix (compare intimus "inmost," ultimus "last"), here denoting "close association with." Maritimes "seacoast regions of a country" is from 1590s; specifically of the southeasternmost provinces of Canada by 1926.