unclean vs untouchable

unclean is not a noun while untouchable is a noun.

Word	Noun	Adjective	Verb	Adverb
unclean	No	Yes	No	No
untouchable	Yes	Yes	No	No

unclean (noun)	untouchable (noun)
	belongs to lowest social and ritual class in India

unclean (adjective)	untouchable (adjective)
having a physical or moral blemish so as to make impure according to dietary or ceremonial laws	forbidden to the touch
soiled or likely to soil with dirt or grime	impossible to assail
	beyond the reach of criticism or attack or impeachment
	not capable of being obtained
	(especially used in traditional Hindu belief of the lowest caste or castes) defiling