oblateness vs roundedness

oblateness and roundedness both are nouns.

Word	Noun	Adjective	Verb	Adverb
oblateness	Yes	No	No	No
roundedness	Yes	No	No	No

As nouns, roundedness is a hypernym of oblateness; that is, roundedness is a word with a broader meaning than oblateness:

oblateness: the property possessed by a round shape that is flattened at the poles
roundedness: the property possessed by a rounded convexity

Other hypernyms of oblateness include bulginess.

oblateness (noun)	roundedness (noun)
the property possessed by a round shape that is flattened at the poles	the property possessed by a rounded convexity