Sangfroid means to keep your cool, or to stay calm under great strain. One can be sangfroid or show great sangfroid. Sometimes dictionaries list a spelling variation as sang-froid with a hyphen. This comes from the original French spelling. However, most of English usage drops the hyphen.
In French sang-froid means cold blood. To be cold-blooded in English is a bad thing, meaning to have no emotion in a situation that should elicit great emotion. However, if one’s blood is cold instead of hot, one could be seen to be calm instead of angry.
English does keep the pronunciation from the French and sangfroid is \ˈsäⁿ-ˈf(r)wä\ (sahn-frah).
Now to be clear, this German sangfroid and – some would say – complacency is not necessarily good either for them or the rest of the world, in the long run. [BBC]
As he continues to commentate for Channel 9 in Australia, cutting back his commitments as he gets frailer, he exhibits exactly the same combination of sangfroid and humour. [The Telegraph]
Part of the appeal is tied up with Martin Shanahan’s supernatural sangfroid. I was not alone in longing for him to respond to Kernen’s bemusement with a slice of aggressive disingenuousness. [Irish Times]
There is no doubting his sang-froid and bravery or his staunchness, as when he writes in May 1916: “If anyone at home thinks or talks of peace, you can truthfully say that the Army is weary enough of war but prepared to fight for another 50 years if necessary, until the final object is attained.” [Washington Times]