's caste system
, an untouchable
, or achuta
is a person outside of the four castes, and considered 'below' them. Untouchables include such people as leather-workers. There are various castes within untouchable, the lowest ranking generally considered to be the Bhangis.
Harijan is the polite form for untouchable coined by Mahatma Gandhi which means "Children of God" (Hari is another name for Vishnu, Hindu God).