Stolid (adjective)

1. Having or showing little emotion or animation; impassive.
2. Unresponsive to emotional appeals; showing little emotion or animation.

Origin:

From latin stolidus ("dull, stupi.d")

Examples:

1. He was always stolid and unresponsive to her attempts to cheer him up.
2. He remained stolid and emotionless during the entire trial.
3. He was criticized for his stolid and unresponsive attitude.
4. The stolid expression on her face made it hard to read her thoughts.
5. He had a stolid and unemotional demeanor, which made it difficult for others to connect with him.