coolness vs nervelessness

coolness and nervelessness both are nouns.

Word	Noun	Adjective	Verb	Adverb
coolness	Yes	No	No	No
nervelessness	Yes	No	No	No

As nouns, coolness and nervelessness are synonyms defined as:

coolness and nervelessness: fearless self-possession in the face of danger

coolness (noun)	nervelessness (noun)
the property of being moderately cold	fearless self-possession in the face of danger
a lack of affection or enthusiasm
fearless self-possession in the face of danger
calm and unruffled self-assurance