imperturbableness vs coolness

imperturbableness and coolness both are nouns.

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

As nouns, imperturbableness and coolness are synonyms defined as:

Other synonyms of imperturbableness include imperturbability.

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