Synonyms:
impassive, stolid
Meaning: having or revealing little emotion or sensibility; not easily aroused or excited; "her impassive remoteness"; "he remained impassive, showing neither interest in nor concern for our plight"- Nordhoff & Hall; "a silent stolid creature who took it all as a matter of course"-Virginia Woolf; "her face showed nothing but stolid indifference"
Usage examples
In the same way, I saw our General once approach the table in a stolid, important manner.
Five o'clock had passed when they emerged upon the New England town's stolid main street.