coldness vs iciness

coldness and iciness both are nouns.

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

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

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

As nouns, coldness and iciness are synonyms defined as:

Other synonyms of coldness include chilliness, coolness, frigidity, frigidness.

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