"Other people know what this means" is not an explanation either. It has been used throughout philosophical and scientific history to fake-explain lots of stuff, from the Platonic Ideal definition of a human to ethnonationalism, but you don't get any knowledge from that either. It relies on people's tendency to feel too dumb to vocalize uncertainty about "obvious" unspoken assumptions.
So please, can you explain "private property"? Without simply rephrasing it ("ownership", "possession", etc.) or referring to an authority ("the courts will mediate and the outcome of that mediation depends", or other ways to dodge explaining something? I have given an example of how to do it.