Sangfroid
/sɑːŋˈfrwɑː/
Definition 1 of 1
Pro Tip 1/3French Origin
Sangfroid comes from French, where 'sang' means blood and 'froid' means cold, reflecting calmness under pressure. 
Her sangfroid during the intense debate impressed everyone.
Pro Tip 2/3Emotional Restraint
Sangfroid implies controlling emotions; it's more about hiding feelings than not having them. 
Even when insulted, he responded with sangfroid.
Pro Tip 3/3Cultural Nuance
Using 'sangfroid' suggests sophistication and might convey an anglophile or literary personality. 
She admired his sangfroid and worldly demeanor.