showing little emotion
phlegmatic - cool
Somebody who is ‘phlegmatic’ has a calm temperament that means they do not react in the same way as others to emotion, stress, or excitement. While this may lead some to consider them dull or uninteresting, it is generally seen as a positive, especially in times of crisis. It is a formal word mostly used in written English.
Our manager can be a little aloof at times, but his calm, phlegmatic manner is very reassuring when the pressure is on.
For a while, I was very angry that I didn’t get the job, but now I can judge the situation a lot more phlegmatically.
People in the financial industry are often considered dull, phlegmatic operators, but the nature of their work requires a degree of pragmatism and restraint.