Akṣara

Imperishable, indestructible, the syllable. From a (not) + kṣara (perishing). In the Bhagavad-gītā (8.3), akṣara is the supreme Brahman — that which does not decay. It is also the name of the sacred syllable oṃ, the primal vibration that persists when all else dissolves into pralaya. The term bridges ontology and phonology: the imperishable is not merely a metaphysical abstraction but a sonic reality that can be heard in the depth of meditation. See brahman, om.