n. pl. — always plural, Geography
the Canadian provinces of Nova Scotia, New Brunswick, and Prince Edward Island.
Type: 3. Semantic Change — The adjective maritime has the general meaning of 'of or relating to the sea'. The term Maritimes has been adopted to collectively refer to the three Maritime provinces, due to their proximity to and cultural and economical ties to the Atlantic Ocean. Nova Scotia and New Brunswick were two of the four original provinces to enter Confederation in 1867, along with Ontario and Quebec. Prince Edward Island joined Canada in 1873. The term is most frequent in Canada (see Chart 1).
The Maritimes collectively cover just over 1% of Canada's land surface (133,850 km2, see Image 1), yet are historically and culturally of great importance to the nation of Canada. See also Canadian Encyclopedia, s.v. "Maritime Provinces".
See also: Confederation Maritime Provinces Maritimer Newfoundland Time
- 1806  (1956)  Schooners come from the Maritimes with much needed provisions and lumber.
- 1865  Hon. Mr. Whitman, of the Legislative Council of Nova Scotia, on being called upon, apologised for being unable to make himself heard in so large a hall. [...] The next toast was "Fraternal intercourse with the Maritimes," which was drunk with all the honours. 
- 1880  We are not in a position to say what proportions these numbers bear to the volume of litigation in each, nor to the number of cases sent by each to England, but taking Ontario as the mean, the number from Quebec seems small, and that from the Maritimes would appear to be large. 
- 1901  Few contractors are as widely known in the eastern provinces as Mr. Jas. Reid, and the firm of James Reid & Sons probably do more business to-day in that line than [...] any other firm in the Maritimes. 
- 1919  In the meantime Hon. Arthur Meighan is planning a speaking tour on behalf of the Union Government in the West. Other Ministers are to tour the Maritimes and Ontario. 
- 1943  Saskatchewan, Manitoba and Ontario had full representation. Two directors were present from British Columbia, Alberta and the Maritimes. 
- 1964  We in the Maritimes are sick of hand-outs. . . .
- 1966  Attempts were being made to locate Mr. Walsh and his wife who are presently on vacation in the Maritimes.
- 1981  Cancellation of a rail service does not sit well in the Maritimes, particularly in this case when the immediate beneficiary of the cuts is central Canada. 
- 2000  A woman and two children exiting a plane in Moncton, N.B., were sent tumbling to the ground Monday when a windstorm that pounded the Maritimes blew over a portable staircase on the tarmac. 
- 2016  For people all over the Maritimes, the winter of 2015 will go down as one doozy of a season. After a relatively quiet start, the season proved to be one of the snowiest and coldest on record, breaking numerous records in the process. Maritimers are used to bearing the brunt of the winter season. 
Images:
Image 1: the Maritime provinces. Source: Wikimedia Commons. Image: QuartierLatin1968
Chart 1: Internet Domain Search, 15 Aug. 2012