Brahman
ब्रह्मन् (brahman)
The ground of all that is - the single reality the Upanishads name beneath the world's changing faces.
Brahman - from a root meaning to grow, to expand - is the Upanishads' name for the ultimate: that from which everything arises, in which it persists, into which it resolves. Not a god among gods but the reality prior to every form, including divine ones.
The texts characteristically approach it by negation and paradox - not this, not that; smaller than a grain, vaster than the sky - precisely because any positive description turns it into one more object, and it is the subject of everything.
For the reader rather than the metaphysician, brahman marks a discipline of scale. Against a background that vast, today's crisis resumes its actual size. The teaching is not that the world is unreal; it is that the world is not the whole story.