bulginess vs oblateness

bulginess and oblateness both are nouns.

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

As nouns, oblateness is a hyponym of bulginess; that is, oblateness is a word with a more specific, narrower meaning than bulginess:

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

Other hyponyms of bulginess include ellipticity.

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