mainland

noun3

1. •
   The continent; the principal land, as distinguished from islands or a peninsula.

   • […]I got to the mainland, where, to my great comfort, I clambered up the cliffs of the shore and sat me down upon the grass, free from danger and quite out of the reach of the water. — 1719
2. •
   The principal island of a group.
3. •
   (Northern-Ireland) Great Britain.

noun1

1. •
   (historical) A historical region of British Columbia, British North America, British Empire.