How do you define 'nothingness'?

Is it the absence of matter?
Is it the lack of ideas?
Or is it the the unimaginable end of all things where even physics and concepts do not exist? But that is saying that they could exist.
In true nothingness, nothingness itself doesn't exist.

reality is nothingness because nothingness is what is defined outside of human thought, reason, rationale, and logic. I simply does not exist to the understanding of a human except that it is the word for the contradistinction to all that is and is in motion.