"Dwija" is a term used by M N Sriniwas in the context of Sanskritisation. What does it mean?

Upper Caste Twice Born Sacred Thread Upper Caste Ritual

Twice Born

The term sanskritisation was coined by M.N. Srinivas. It may be briefly defined as the process by which a ‘low’ caste or tribe or other group takes over the customs, ritual, beliefs, ideology and style of life of a high and, in particular, a ‘twice-born (dwija) caste’.