Simply put “conus” means contiguous United States or Continental United States in other words states sharing a common boundry.
A “conus beam” is a beam from the satellites in which the diameter of the beams cover the United States. This can also be called the “footprint” of the beam. This is the area that is covered by the signals that are transmitted. The service providers satellites have a combined footprint that covers all of North America, including parts of Alaska and Hawaii.
Think of it like this; if you took a flashlight and pointed it at the ground, the lighted area would be the footprint. Because geo-stationary satellites are so far from the earth (22,300 miles), they have a very large footprint.