Śūnya means ‘void’, ‘bereft’, and in mathematical scientific literature, ‘zero’. It derives from śūna, being the past passive participle of root śvi, ‘to grow’, ‘to swell’, according to Pänini (7.2.14). So śūna means swelled, swollen, increased, grown. According to Ṛgvedaprātiśākhya (14.2) it indicates a fault in Vedic recital, consisting in an utterance with a swollen mouth. The term śūnya occurs within Upanisadic literature in the Maitryupaniṣad (2.4; 6.31; 7.4), together with other epithets referred to brahman, epithets that mean ‘pure’, ‘clear’, pacified’ (śuddha, pūta, śānta). Etymologically śūnya should therefore mean a void space, a hole determined by a borderless opening, by an unlimited disclosing. According to lexicographers (Amarakośa 3.1.56), its synonyms are ‘sapless’, ‘meaningless’, ‘void’, ‘vane’, ‘hollow’ (asāra, phalgu, vaśika, tuccha, riktaka). This kind of voidness is conceived first of all as a sort of deprivation, as we can see from a well-known literary ‘good saying’ (subhāsita) centred around the term śūnya: ‘Void is the house for he who is sonless, void is the time for he who is friendless, void are the four cardinal points for he who is silly, void is the whole world for he who is poor’ (Śūdraka, Mṛcchakaṭikā 1.8). The reference to the cardinal points (diś) is not at all a trivial one, because it explains why the term śūnya could be made synonym with ‘ethereal space’, ‘atmospheric space’, ‘heaven’ (ākāsa, kha, vyoman).