LOD question

https://en.wikipedia.org/wiki/Level_of_detail

In general, Level of Detail is based on using simplified versions of meshes (i.e. fewer vertices) when you no longer need the full quantity of them to see an adequate amount of detail.

Under ideal conditions, this transition should appear to be seamless, where the next quality level down would not appear to result in any change to the model at that distance. For example, if you have a rounded edge on a crate, then at some distance you would no longer be able to tell the difference between that crate with rounded edges or a perfect cube.

For what it's worth, "culling" or "clipping" are generally the terms related to faces not being rendered. (Note that it's "faces" rather than vertices in this case. You can't easily remove vertices from a mesh and have the faces fill in the gaps)