A war involving the major nations of the world.

(idiomatic) The rest of the world outside of some closed, restricted, or remote environment. / (philosophy) The world external to the human mind.

Of, or relating to the ancient world or former times

The Eastern Hemisphere, especially Europe, Africa and Asia. / The known world before the discovery of the Americas.

An event or competition where competitors and/or teams from several different countries to establish a world champion. / The trophy awarded to the winner of such an event.

Alternative form of real-world

The realm of human experience comprising physical objects, and excluding theoretical constructs, hypotheses, artificial environments, and "virtual" worlds such as the Internet, computer simulations, or the imagination.

(idiomatic) To be loved or cared about a great deal by.

The Americas and Oceania.

(idiomatic) (It's of) minor importance, at least not as important as it first seemed.