Śūnyatā, emptiness, is the central idea of the Perfection of Wisdom and of Madhyamaka: nothing exists by its own nature, apart from causes, parts and conception. Emptiness is not nothingness; it is the very way things exist, through dependence. Nāgārjuna identified it with dependent origination and called it the middle way.
Śūnyatā
Emptiness: the Mahāyāna teaching that all things lack independent, inherent existence.
Also: Shunyata, sunyata