suspicious vs suspiciousness

suspicious is not a noun while suspiciousness is a noun.

Word	Noun	Adjective	Verb	Adverb
suspicious	No	Yes	No	No
suspiciousness	Yes	No	No	No

suspicious (noun)	suspiciousness (noun)
	being of a suspicious nature

suspicious (adjective)	suspiciousness (adjective)
openly distrustful and unwilling to confide
not as expected