coldness vs gelidity

coldness and gelidity both are nouns.

Word	Noun	Adjective	Verb	Adverb
coldness	Yes	No	No	No
gelidity	Yes	No	No	No

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

Other hyponyms of coldness include chill, iciness, chilliness, coolness, nip, frostiness, cool.

coldness (noun)	gelidity (noun)
the absence of heat	coldness due to a cold environment
a lack of affection or enthusiasm
the sensation produced by low temperatures