I think that in the context of AR they actually are trying to talk about "universes that describe a universe". A "metaverse" is a "universe" in the sense that

I think that in the context of AR they actually are trying to talk about "universes that describe a universe". A "metaverse" is a "universe" in the sense that it's a shared 4D spacetime that you can explore (using some technology to give you a window into it). It's "meta" because it's layered on top of our "base universe": It's there to describe and augment the physical universe we exist in. For example: If, in your vision (via glasses, or a HUD, or a pane of glass or a brain implant), there's a big 3D arrow hovering above a road then the arrow exists in the "metaverse" and the road exists in the physical universe that the metaverse is describing.