You're literally going to use a dictionary definition that was coined up a few hundred years ago before we even knew how to fly, right? Your taking associations from a language and not being accountable for it's obseletion. The point is, with only space and time, mass exists. Therefore something affectable exists. Without ever having the ability to take anything away, with us being at the base point of simplicity at it's most, is a boiling pot of what is potential particles coming in and out of existence at the same time. When you break down to the most simplest of states, you're left at the fringe of where reality and lack of reality merge, where tangible things and impossible non-existence vibrate in a superstate together. 

Go on, keep saying nothing is nothing. Keep looking at a book dictated years and years ago where people would look at a large canyon, or the sky, or a dark hole, that's still filled with moisture, particles, atoms, radiation, beams, acting forces, and say "That's nothing" in comparison to something a little more substantial to which they say "and that's something!", and keep thinking to yourself "wow hey these people sure did know what was nothing!". 

But what happened? Gasp! The sky turned out to have something in it, particles!

But the cosmos empty in between all those stars and rocks! Gasp! Even then there's radiation!

But then take away the radiation then! Gasp! Atoms still!

Take away the atoms! Gasp! Still something!

Take away all you possibly can! Gasp! Still something. 

Face it, the more we strip away, the more you say "but you can't have something from nothing", do you realize that "hey, what we thought as nothing...never existed". 

Update your associations with words with the results the universe give you. Cheers!