In the Hindu religion, Brahman (bráhman) is the unchanging, infinite, immanent, and transcendentreality which is the Divine Ground of all matter, energy, time, space, being, and everything beyond in this Universe.^[1] The nature of Brahman is described as transpersonal, personal and impersonal by different philosophical schools. In the Rig Veda, Brahman gives rise to the primordial beingHiranyagarbha that is equated with the creator God Brahmā. The trimurti can thus be considered a personification of Hiranyagarbha as the active principle behind the phenomena of the universe.

The word "Brahman" is derived from the verb ((brh)) (Sanskrit: to grow), and connotes greatness. The Mundaka Upanishad says:

Om- That supreme Brahman is infinite, and this conditioned Brahman is infinite. The infinite proceeds from infinite. Then through knowledge, realizing the infinitude of the infinite, it remains as infinite alone.

Sanskrit bráhman (an n-stem, nominative bráhmā) is from a root bṛh " to swell, grow, enlarge". brahmán is a masculine derivation of bráhman, denoting a person associated with bráhman. The further origin of bṛh is unclear. It could be from PIE *bherg'^h- "to rise, high, eminent", cognate to Old Norse Bragi. Some, includingGeorges Dumézil, have said that the Latin word flāmen "priest" may also be cognate.

http://en.wikipedia.org/wiki/Brahman