that is supposed to exist independent
of sensory perception
The opposite of this idea is represented in the Theory of Relative Reality. The reason absolute reality isn't just a theory is that subjective realities are always thought to be absolute by their owners.
This concept tends to go beyond words. It is very seldom that one would deny the stability of their own existence, of their own perception. Religion is often involved in the process of separating misconceptions and illusions from what is widely known as "The Truth."