impermissible vs untouchable

impermissible is not a noun while untouchable is a noun.

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

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

impermissible (adjective)	untouchable (adjective)
not permitted	forbidden to the touch
not allowable	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