lukewarmness vs frigidness

lukewarmness and frigidness both are nouns.

Word	Noun	Adjective	Verb	Adverb
lukewarmness	Yes	No	No	No
frigidness	Yes	No	No	No

As nouns, frigidness is a hypernym of lukewarmness; that is, frigidness is a word with a broader meaning than lukewarmness:

Other hypernyms of lukewarmness include chilliness, coldness, coolness, frigidity, iciness.

lukewarmness (noun)	frigidness (noun)
a warmness resembling the temperature of the skin	a lack of affection or enthusiasm
lack of passion, force or animation	sexual unresponsiveness (especially of women) and inability to achieve orgasm during intercourse
	the absence of heat