It can be even looser than that, it can even just mean any server-side call that is inherently cache-able, meaning the same request will return the same data.

It can be even looser than that, it can even just mean any server-side call that is inherently cache-able, meaning the same request will return the same data. "Static" meaning "Not changing over time" rather than "Dynamic" meaning "changing over time". That usage is not common outside of math, but I have on occasion seen it used this way when discussing web programming.