sang-froid (n.)youdaoicibaDictYouDict[sang-froid 词源字典]
"presence of mind, composure," 1712, from French sang froid, literally "cool blood," from sang "blood" (from Latin sanguis; see sanguinary) + froid "cold" (from Latin frigidus; see frigid).[sang-froid etymology, sang-froid origin, 英语词源]