A disease that spreads rapidly around the world is known as a PANDEMIC DISEASE. The word "pandemic" is an adjective that has a late latin origin from the word "pandemus" which means pertaining to all districts or people. The root "demos" is known to refer to districts or the people within them. I remember the difference between pandemic, epidemic, and endemic by breaking down the words. Pandemic refers to all districs, or countries, continents, and communities in our case. Epidemic means among multiple communities, and endemic means within a single community.