Terminology for empty space at the edge of the observable universe? Is there a name for a point at the edge of the observable universe at which there is no visible matter, that appears completely dark?

I'm thinking something like "empty space", but that could equally apply to an empty void between galaxies, which isn't quite what I'm looking for.

So it would refer to a theoretical line in space from the observer to the edge of the universe which contains no visible matter. Is there a term for this?
There is no name for this.

As we look further in space, we also look further back in time. The "edge of the observable universe" is in the early universe. At an early time in the evolution of the universe, the whole of space was so hot and dense that it was opaque.  In whichever direction we look, we can't look back further than this. The is called the cosmic microwave background. There is no direction in which we can look in which we don't see the cosmic microwave background. There is no direction that contains no visible matter.

There are directions that contain no galaxies or other more nearby objects, but there is no name for these directions.