Gayatri (Gāyatri), mn. protection of lifeforce, where Gāya refers to Prāṇā or lifeforce and tri is from trayas meaning protection. In common use Gāyatri refers to the Vedic mantra for Savitur
and aspect of the Sun God, that following initiation and investiture of the Sacred
thread, Yajñopavita, makes one a Brahmin/Brahmaṇa. More accurately, the Gāyatri is
one among several Chandas or meter/rhythm which several mantras are composed in.