n. & adj. — Montreal, Transportation
the underground rapid transit system in Montreal.
Type: 1. Origin — Montreal inaugurated its rapid transit system in 1966, calling it, in analogy to the Paris underground system, metro. Toronto refers to its rapid transit system, inaugurated in 1954, as the subway. According to Boberg (2010: 497), the official use of the term metro predisposes English-speaking Quebecers to adopt the term instead of the originally American English term subway that was adopted in Toronto. The term is unrelated to meanings already existing in Canadian English (see, e.g. Metro meaning 2), which means that the term is a new loan word from French that is homograph, i.e. only coincidentally written the same way, to already present forms such as Metro (meaning 2); their transition paths are not related. The present term and meaning is, therefore, Type 1 - Origin (rather than Type 3 - Semantic Change).
In the Rest of Canada, metro is understood to mean subway in certain cases, but is frequently used to refer to the metropolitan area of a city, e.g. Greater Vancouver is now called Metro Vancouver, or the Metro area, as in the Halifax region (see Metro, meaning 2). In Montreal English, the term has undergone semantic change to denote rapid transit.
See also Gage-5, s.v. "metro" (3), which is described as "the subway train system in Montréal".