What are you getting at?
You are correct, definitions of safe will vary. I agree with HoughMade, any firearm that has a round is the chamber is dangerous....and it should be. If it's not dangerous, then what is the point of carrying it?
Just because something is dangerous does not mean anyone will get hurt...assuming you are following proper safety protocol while doing so. Handling explosives is dangerous, but can be done successfully on a frequent basis when proper safety protocol is used.
My definition of "safe" means there are no rounds in the chamber, and there is no magazine inserted and/or the cylinder is open with no rounds inserted. Only then do I consider a handgun "safe" (all of which must be double checked and verified). And even then, there are still safety protocol to follow. Not because the handgun itself presents an extra danger. But rather, it is to maintain the habit of handling that handgun safely. That way, once the gun is made dangerous again, you have built the habit and muscle memory for proper safety protocol.