Proper noun
(historical) A town in Quebec. A former town that was merged into the former city of Mercier, on the Island of Montreal, in Quebec, Canada.
(historical, informal) The former eastern region of the former city of Mercier, Quebec, Canada; on Montreal Island.
(informal) Synonym of Mercier East (“Mercier-Est”) A neighbourhood of Quebec, in the district of Mercier, in the city of Montreal, existing to the east Longue Pointe and Autoroute 25.
Source: en.wiktionary.org