If I may add to this semantic debate. Acoustic means it is related to sound/hearing. Nothing more elaborate or precise than that.
Having said that, most of us take "acoustic" guitar as the piece of wood (or whatever that material is) with strings over it and a few more necessary parts and without any electricity involved. Of course, some concerts have even that "acoustic" guitar associated with a microphone.
If you check virtually any concert involving guitars, you will see multiple instruments swapped throughout the performance. They were picked for some reason and even two "acoustic" guitars will not sound quite the same. Now, it is on you to figure out which one is the more real one.
Having said that, most of us take "acoustic" guitar as the piece of wood (or whatever that material is) with strings over it and a few more necessary parts and without any electricity involved. Of course, some concerts have even that "acoustic" guitar associated with a microphone.
If you check virtually any concert involving guitars, you will see multiple instruments swapped throughout the performance. They were picked for some reason and even two "acoustic" guitars will not sound quite the same. Now, it is on you to figure out which one is the more real one.