The definition of First World is an industrialized and advanced developed country.
North America is an example of a continent in the First World.
[occas.f- w-] the countries of the world that are well developed economically and industrially and that have a relatively high standard of living
also first world
- The wealthiest and most highly-developed nations in the world.
- During the Cold War, the industrialized capitalist nations of the world.
- Those countries aligned with the West during the Cold War, particularly in contrast to those aligned with the East (Second World).
- Wealthy, developed nations, contrasted with the Third World.