Matt_mcl’s recent announcement (in MPSIMS) that he was running for Parliament in his home riding led me to wonder again about the Canadian usage here.
I know that for Parliamentary purposes the gigantic county of Yorkshire (England) was divided into three “ridings” – whose name derives from trithings, a Tolkienesque word that apparently was local for “thirds.” (They are separate counties now.) Is this the origin of the Canadian term? If so, how did it migrate from there to Canada? If it isn’t, where in the world did the term come from?