Hindu initiation ritual, restricted to the three upper varnas .
It marks a male's entrance into the life of a student and his acceptance as a full member of the religious community. After a ritual bath, the boy, aged 524, is dressed as an ascetic and brought before his guru , who invests him with various symbolic articles. The initiate receives a sacred thread, worn throughout his life, that identifies him as twice-born, the second birth being effected by receipt of a mantra . Observance of upanayana is decreasing and is now largely confined to the Brahman class.