ostentatiousness vs pretentiousness

ostentatiousness and pretentiousness both are nouns.

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

As nouns, ostentatiousness and pretentiousness are synonyms defined as:

ostentatiousness and pretentiousness: lack of elegance as a consequence of being pompous and puffed up with vanity

Other synonyms of ostentatiousness include inflation, ostentation, pomposity, pompousness, puffiness, splashiness.

ostentatiousness (noun)	pretentiousness (noun)
lack of elegance as a consequence of being pompous and puffed up with vanity	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