world-war adjective 1world war noun 1forms 2 adjective1 •Pertaining to a period of time immediately during a world war world war noun1 •A war involving the major nations of the world.Their lips met in one long silent kiss, and a moment later he had gone to strike the first blow in the coming world-war, and to bring the beginning of sorrows on the Tyrant of the North. — 1894 formsworld wars · world-wars