Phlegmatic
Etymology
From Greek phlegma, originally "flame" or "inflammation," which came to name one of the four humors of ancient and medieval medicine: phlegm. A person thought to have an excess of phlegm was believed to be sluggish, cool, and slow to anger — the phlegmatic temperament. The medical theory is long dead, but the personality type it named lives on in the word.
adjective · /fleg-MAT-ik/
Calm, unemotional, and hard to stir to feeling or action.
What it names
A settled, cool-tempered composure — the temperament of someone who stays impassive where others would react.
Example
The pilot’s phlegmatic voice over the intercom did more to calm the cabin than the announcement itself.
Related idea
Stoic implies deliberately enduring hardship without complaint; phlegmatic is a natural, temperamental calm and lack of excitability.