grandness vs immensity

grandness and immensity both are nouns.

Word	Noun	Adjective	Verb	Adverb
grandness	Yes	No	No	No
immensity	Yes	No	No	No

As nouns, grandness and immensity are synonyms defined as:

Other synonyms of grandness include enormousness, greatness, immenseness, sizeableness, vastness, wideness.

grandness (noun)	immensity (noun)
the quality of being magnificent or splendid or grand	unusual largeness in size or extent or number
unusual largeness in size or extent or number
splendid or imposing in size or appearance
a prominent status