castaway vs Harijan

castaway and Harijan both are nouns.

Word	Noun	Adjective	Verb	Adverb
castaway	Yes	No	No	No
Harijan	Yes	No	No	No

As nouns, Harijan is a hyponym of castaway; that is, Harijan is a word with a more specific, narrower meaning than castaway:

Other hyponyms of castaway include heretic, misbeliever, religious outcast, leper, untouchable.

castaway (noun)	Harijan (noun)
a shipwrecked person	belongs to lowest social and ritual class in India
a person who is rejected (from society or home)