(CALMNESS) [noun] [U] [formal] - the ability to stay calm and not get emotional or excited about things even in a difficult or dangerous situationHe looked like an English country gentleman but was totally lacking in the phlegm and equanimity associated with one.Such phlegm in the face of adversity could only be admired.
PHLEGM
Meaning of PHLEGM in English
Cambridge English vocab. Кембриджский английский словарь. 2012