1) French word used in English 
• (n.) Freedom from agitation or excitement of mind; coolness in trying circumstances; indifference; calmness.
Sang`-froid' noun [ French, cold blood.] Freedom from agitation or excitement of mind; coolness in trying circumstances; indifference; calmness. Burke. 
sang-froid 1. Self-possession or calmness, especially in a dangerous or stressful situation. 2. Coolness and composure, especially in trying or difficult circumstances. 3. Etymology: French sang, 'blood'; from Old French, from Latin sanguis, 'blood' + froid, 'cold'; from Old French, from Vulgar Latin frigidus, alteration of Latin frigidus.