Semantics aside, you asked me what nothing was, and I told you. Now you are saying that nothing is a something to be absent. nothing is the absense of something.
It's not sematics. Your definition of nothing, the absence of anything known or unknown (first, if it was unknow, how would you know it wasn't there?) must logically include the absence of nothing since nothing is something known (it must be since you just defined it).
Is nothing also the absence of God? Does time pass in nothing?
Matter cannot come from nothing. So whatever began matter, in my mind could be considered God. Thomas Aquinas was probably more eloquent then myself.
Well let's back up. You have yet to tell me what nothing is, much less have a basis for a sweeping generalization about it. Besides, why should matter "have a beginning"?