Sunnata

Suññatā: noun: voidness, empty, emptiness. As a doctrinal term it refers, in Theravada, exclusively to the anatta doctrine,.i.e. the unsubstantiality of all phenomena: Void is the world . . . because it is void of a self and anything belonging to a self; suññam attena vā attaniyena vā S. XXXV, 85; also stated of the 5 groups of existence khandha in the same text. See also M. 43, M. 106. - In CNidd. quoted in Vis.M XXI, 55, it is said: Eye... mind, visual objects... mental-objects, visual consciousness... mind-consciousness, materiality... consciousness, etc., are void of self and anything belonging to a self; void of permanency and of anything lasting, eternal or immutable.. They are coreless: without a core of permanency, or core of happiness or core of self.; - In M. 121, the voiding of the mind of the fermentations, in the attainment of Arahatship, is regarded as the;fully purified and incomparably highest concept of voidness. - See Sn. v. 1119; M. 121; M. 122 WHEEL 87; Pts.M. II: Suñña-kathā; Vis.M XXI, 53ff.

References

Maha Thera Nyanatiloka. Manual of Buddhist Terms and Doctrines, Buddhist Publication Society, first edition 1952.