Pandemic, Global Epidemic, Epidemic, Endemic
Solution 1:
A global epidemic is a pandemic. According to the Mayo Clinic:
A pandemic refers to a global epidemic — one that has spread over several countries or continents affecting a large number of people. Dr. Pritish Tosh adds, "In epidemiologic terms, an outbreak refers to a number of cases that exceeds what would be expected. A pandemic is when there is an outbreak that affects most of the world. We use the term endemic when there is an infection within a geographic location that is existing perpetually."
The WHO “declares” a pandemic, which may have certain consequences in the actions taken by member states. Whether WHO declares it or not a disease may be a pandemic.
The set of words may be used metaphorically to describe problems such as child abuse or spousal abuse that are widespread but not contagious as are dIseases arising from viruses, bacteria, and fungi.
Solution 2:
"endemic" is an adjective that means that the condition is found commonly in an area or community. It's not specific to the size of the community. It's possible for something to be endemic in the whole world.
So if COVID-19 doesn't go away, it will become endemic in all the communities that have not eradicated it, just as the common cold is.
As for your other terms, the distinction between epidemic and pandemic is fuzzy and there's some overlap. Merriam-Webster describes it this way:
An epidemic is defined as “an outbreak of disease that spreads quickly and affects many individuals at the same time.” A pandemic is a type of epidemic (one with greater range and coverage), an outbreak of a disease that occurs over a wide geographic area and affects an exceptionally high proportion of the population. While a pandemic may be characterized as a type of epidemic, you would not say that an epidemic is a type of pandemic.