hardened

This word describes a transformation from a soft or vulnerable state to one of rigidity. When applied to materials, it suggests a permanent chemical or physical change, such as concrete setting or steel being tempered. It implies a loss of flexibility and a gain in structural strength.

When applied to people, it carries a heavy negative connotation of emotional deadness. It suggests that a person has seen so much brutality or hardship that they are no longer capable of empathy or remorse. It is far more severe than being tough; it implies a psychological scarring that makes a person impervious to guilt or kindness.