pretentiousness vs pretentious

pretentiousness is a noun but pretentious is not a noun.

Word	Noun	Adjective	Verb	Adverb
pretentiousness	Yes	No	No	No
pretentious	No	Yes	No	No

pretentiousness (noun)	pretentious (noun)
the quality of being pretentious (behaving or speaking in such a manner as to create a false appearance of great importance or worth)
lack of elegance as a consequence of being pompous and puffed up with vanity

pretentiousness (adjective)	pretentious (adjective)
	making claim to or creating an appearance of (often undeserved) importance or distinction
	intended to attract notice and impress others
	(of a display) tawdry or vulgar