Shunyata in Sanskrit means literally ‘void’ or ‘emptiness,’ that is to say, ‘space,’ the absence of all conceptualized attitudes.
Trungpa provides the canonical definition of shunyata as the radical absence of conceptualized attitudes, linking it to Nagarjuna’s Madhyamika and to the Heart Sutra’s progression from emptiness to mantra.
, Cutting Through Spiritual Materialism, 1973thesis