ontario
n. uncountablen. a large province in east-central Canada that is home to the country's capital and its biggest city. It is also the name of one of the five Great Lakes in North America.
n. a province in east-central Canada, bordered by the Great Lakes and Hudson Bay; also refers to the smallest of the five Great Lakes. When referring to the province, it is the most populous subnational division in Canada.
Toronto is the largest city in Ontario.
Many people move to Ontario to find work in the country's financial and political centers.
The industrial heartland of Ontario accounts for a significant portion of the national GDP, largely due to its proximity to the American border and the Great Lakes shipping routes.
Probably from Wyandot ontari꞉io (literally “great lake”). If so, ultimately from Proto-North Iroquoian -õtaɹeʔ and Proto-Iroquoian -õːtaɹiʔ.
As a proper noun, it is always capitalized and typically used without an article.