In Canada, the federal union of provinces and territories which formed Canada, beginning with New Brunswick, Nova Scotia, Ontario, and Quebec, and later including all the others.
In Canada, the date of Confederation; 1 July 1867.
In Newfoundland, the political union of Newfoundland with Canada.
In Newfoundland, the date of Confederation; 31 March 1949.
The Senate of Canada; the upper house of the Canadian parliament; "the Senate".
Any of several legislative bodies. (In countries which have multiple legislative bodies, the Senate is often the more senior.)
The United States Senate.
The upper legislative body of many of the states of the United States.
The council that governed the ancient Roman Republic.