Meaning of phlegmatism in English:
phlegmatism
Pronunciation /ˈflɛɡmətɪz(ə)m/
noun
Phlegmatic nature, character, or temperament; calmness, stolidity, absence of excitability.
Origin
Late 17th century; earliest use found in Randle Holme (1627–1700), herald painter. From phlegmat- + -ism.