Grounding and Earthing are probably used interchangeably on this site and I agree they could be merged, possibly after looking at some statistics which I don't know how to do.
I think there's a big difference between questions about ground and questions about grounding. They are not synonyms, and if they are used as such, the questions should be re-tagged with the correct one.
While most circuits have a "ground" reference, not everything is grounded to Earth. Thus they aren't necessarily synonymous.
Common bench power supplies may have both "ground" (-) and "Earth" (green) jacks, but coupling them may be optional, since they are not the same thing.
Maybe that's not enough to keep the tags separate though...