sang-froid vs aplomb

sang-froid and aplomb both are nouns.

Word	Noun	Adjective	Verb	Adverb
sang-froid	Yes	No	No	No
aplomb	Yes	No	No	No

As nouns, sang-froid and aplomb are synonyms defined as:

Other synonyms of sang-froid include assuredness, cool, poise.

sang-froid (noun)	aplomb (noun)
great coolness and composure under strain	great coolness and composure under strain