Difference between Pompousness and Ostentation

POMPOUSNESS vs OSTENTATION: NOUN

The quality of being pompous
Synonyms See pompous.
The character of being pompous; also, pompous conduct; magnificence; splendor; great display or show; ostentatiousness.
Lack of elegance as a consequence of being pompous and puffed up with vanity

A gaudy outward display
A show or spectacle.
The act of ostentating or of making an ambitious display; unnecessary show; pretentious parade; -- usually in a detractive sense.
Synonyms Show, Display, Parade, Ostentation, flourish, dash. Show is the most general word for the purposed exhibition of that which might have been kept private; as such, it includes the others. Ostentation is always bad; the others may be good in certain relations. Parade and display are more suggestive of the simple act, ostentation of the spirit: as, to make a parade of one's learning; it was ostentation that led the Pharisees to make a parade or display of their charities and prayers. Parade is a matter of vanity; ostentation, of vanity, pride, or ambition.
Ambitious display; pretentious parade; vain show; display intended to excite admiration or applause.
A sight or spectacle; show; ceremony.
Display; especially, public display.
The act or an instance of showing; an exhibition.
Pretentious display meant to impress others; pretentious showiness.
A showy outward display
Lack of elegance as a consequence of being pompous and puffed up with vanity
Pretentious or showy or vulgar display

Sanctimoniousness, Egotism, Presumptuousness, Boastfulness, Bombast, Smugness, Superciliousness, Pretension, Grandiloquence, Haughtiness, Splashiness, Ostentatiousness, Ostentation, Pretentiousness, Pomposity

Gaudiness, Frivolity, Pretension, Flashiness, Showiness, Conspicuous consumption, Flamboyance, Opulence, Extravagance, Splashiness, Fanfare, Pomposity, Pompousness, Pretentiousness, Ostentatiousness

Pedantry, Vapidity, Sanctimony, Affectation, Imperiousness, Priggishness, Sanctimoniousness, Presumptuousness, Bombast, Smugness, Superciliousness, Pretension, Grandiloquence, Ostentatiousness, Ostentation

Vainglory, Frippery, Sumptuousness, Grandiloquence, Glitz, Grandeur, Frivolity, Pretension, Flashiness, Conspicuous consumption, Flamboyance, Opulence, Extravagance, Pompousness, Ostentatiousness

And to cure himself of at least one type of pompousness, he should really try some Chicken Tikka Masala.

Nevertheless, ostentation and magnificence seemed to increase in the country, while its resources were diminishing.
All of the above five points put their focus on practicality before ostentation.
His religious character was free from ostentation, but uniform, consistent, sincere, and ardent.
If for others, it is an unjustifiable expression of ostentation or seduction.
He took pleasure in giving generously, but always judiciously and without ostentation.
And observe that there was no ostentation in the course he pursued.
SYN: Ostentation, magnificence, parade, ceremony, show, display, gorgeousness, grandeur, splendor, pageantry, publicity.
SYN: Vaunting, flaunting, display, pomp, ostentation, show, pageant, procession, spectacle.
Learning to Avoid the Dangers of Ostentation, Etc.
It is not knowledge they desire but ostentation.