lose caste

verb2

1. •
   To lose one's status as a member of one's caste of birth.

   • An uncle of mine in Delhi thinks that I have become polluted, that I have lost caste by working with leather. — 1993
2. •
   To fall in social standing; to suffer a loss of status or reputation.

   • He was degraded in their eyes; he had lost caste and station before the very paupers; he had fallen from all the height and pomp of beadleship to the lowest depth of the most snubbed hen-peckery. — 1838