And we make it worse by called a hopefully equipotential plane (layer) on a PC board the "ground plane" when it is not a true Ground unless it is connected to Earth (which is relatively uncommon--excuse me, I should say,"unusual").
Max, you should always provide a picture to properly illustrate the concept of "ground." Here's one innovative approach to providing an "earth ground." (Maybe the dirt has magic electrical properties?)
I was always taught that since electric current is defined as "the flow of electric charge through a medium", you shouldn't say "current flow" because then you effectively have "flow flow" ... but I can never break myself of the habit of saying "the current flows..."
I was lucky enough a few years ago to see a presentation by Bruce Archambeault on EMC and signal integrity. I think he put it best - "Ground is where you grow potatoes. Current flows back to a source through a return path. Many times that path is not what you intended."
-- Sloppy terminology here will lead to sloppy thinking and subsequent problems.
I agree. Just recently we reviewed some circuit designs that had a power source using another power source's "ground" line for a return. At least, that's what it looked like according to the names of all the sources and returns. The meeting ended with a "We have to look into this". More confusion and wasted time.