In Jainism, the word "Tejas" (तेजस्) generally means "energy," "lustre," "brilliance," or "radiance." It also refers to the element of fire (agni) among the five primary substances (Panchamahabhuta) recognized in Jain philosophy: earth (prithvi), water (ap), fire (tejas), air (vayu), and space (akasha).

Additionally, "Tejas" can denote the fiery body (Tejas Sharira), which is a type of body possessed by certain beings in Jain cosmology, especially celestial beings and some hellish beings. This body is made of subtle fire particles and is associated with energy and heat.

Thus, in Jain context, Tejas signifies both a physical element and a quality of brilliance or spiritual energy.