Thirunamam Thiru (word representing sacredness) + Namam (name), --> The Sacred name. It represents the 'Sacred name of God'. The phrase Namam also represents the white clay found at the deeper layer of earth, which is used as the powder to wear a flame shaped mark. The Ayyavazhi people wore this Namam, starting from the central point between the eyebrows, going straight up near the top edge of the forehead.
The flame shape represents Aanma Jyothi or Atman. Which in turn means that, Aatman is considered sacred and as the name of God. Zealous devotees smeared it on the exterior of the upper arms, over the chest and below the spinal cord area at the back.
This white mark was unlike the one worn by a Hindu of Vaishnavism tradition who wore it on the forehead in the shape of 'U', or of Saivism tradition who wore it horizontally as three parallel lines. This Thirunamam is also called as Tottu Namam and Thiruman.
Read more about Thirunamam: Social Synonym, Religious Understanding, As A Ritual, In Ayyavazhi Symbolism, See Also