"Nothing", used as a pronoun subject, is the absence of a something or particular thing that one might expect or desire to be present or the inactivity of a thing or things that are usually or could be active. As a predicate or complement "nothing" is the absence of meaning, value, worth, relevance, standing, or significance. "Nothingness" is a philosophical term for the general state of nonexistence, sometimes reified as a domain or dimension into which things pass when they cease to exist or out of which they may come to exist, e.g., God is understood to have created the universe ex nihilo, "out of nothing".
