Pandemic, when used as a noun, refers to a disease which runs rampant, affecting continents or even the world, as was the case with the Spanish flu of 1918. A pandemic is distinguished from an epidemic in spreading much farther and affecting many many more people. Pandemic, when used as an adjective, does not have the connotation of disease. As an adjective it means universal, or nearly so, as in a pandemic fear of nuclear war.