An outcast is someone who is rejected or cast out, as from home or looked down upon, or ignored. In common English speech, an outcast may be anyone who does not fit in with normal society, which can contribute to the sense of isolation.
Outcasts, in a India caste system, are individuals or a group that for some reason were rejected by any other caste. it is for contrary to caste system, where even pariahs hold their own caste. Foreigners not ruled by the Indian nobility in India & all foreigners were sometimes perceived as outcastes together with untouchables.