Gayatri Mantra

Oṃ = Om is braḥma. 

Bhūr Bhuvaḥ Suvaḥ = Earth Antarikṣa and Swarga. The Entire Universe is denoted by enlisting the 3 major abodes.

Tat = Satya, That Absolute Reality.

(One which cannot have any type of absence or obstruction).

Savitur = The Source (of the aforementioned 3 abodes and the universe). By this even Preserver and Destroyer should be understood.

Vareṇya = the one who is worthy to choose or able to choose. He is Flawless and Greatest, therefore we choose him as our Lord, Saviour and Beloved, as only the flawless one can liberate us from the clutches of Saṃsāra, therefore only He is worthy to be chosen.

Also, only He is worthy to choose. We are under his protection and can Become His someday if someday He chooses us. Only the Supreme can choose because only He has the Ability to Elevate Everyone. 

Bhragah = He who removes our delusion, even scholars are deluded in the form of Supreme! Consider His form to be of Material Nature, like Krishna says to Arjuna "avajānanti mām mūdhāh mānuṣīm tanum āshritaḥ". There are no Material Qualities in Him, and still He has a form, name and action..

the one who removes this and such other delusions. 

Devasya = the one who is self-luminous and one who sports with his own self. Ishwara performs Leela with His own Self. Leela is of 10 types and one who is always playing with himself is Deva here. Deva also means Omniscient/Allknowing. 

Dhīmahi = we meditate upon 

Dhiyo Yo nah Prachodayāt = one who elevates our minds senses intelect bodies and inspires us to the Paramārtha. By Bhargaḥ, it is conveyed that those who contemplate on Him, he frees them from all delusions and from Prachodayāt, it is conveyed that He provides them with proper Intelect, He elevates the mind, intelect, senses.etc and Thus Inspires Him. 

Inspires Him for His Ultimate Purpose, that is Unconditonal Undivided Devotion Bhakti to the Lord, The Supreme.

The Source, Preserver and Destroyer of Entire Universe, the Absolute Reality, The Greatest, the one who chooses His people and is chosen by His Devotees, The Most Beloved, The Supreme, We contemplate on That Ultimate Reality. The one who removes all our Delusions, the one who elevates our Minds, Intelect and Senses and Inspires us to the path of Unconditional Bhakti, we Meditate on that Ultimate Reality. Om.