Meaning of Gayatri, the Mahamantra:
OM : Symbol of Parabrahaman (the Supreme God)
Bhur: Bhuloka or the physical plane (Earth)
Bhuvah: Antariksha/Antaral or the Astral plane pertaining to stars, in between Earth and Heaven
Svah: Celestial plane (Heaven)
Tat: That--Transcendental Paramtama (Ishwar)
Savitur: God as Creator (the Creator of the Sun, the Maker, the Author and the Cause of the Universe)
Varenyam: Fit to be worshipped/adored/revered
Bhargo: Dispeller of darkness, Destroyer of sins, and Remover of ignorance
Devasya: Resplendent, Shining, Self-Luminous (which illumines all and which cannot be illumined by any other means), Radiant and Glorious.
Dheemahi: We meditate
Dhiyo: Intellect or Buddhi
Yo: Who
Nah: Our
Prachodayaat: Enlighten or Illumine
Om : Symbol of Parabrahman (the Supreme God)