rigid

adjective

1. incapable of or resistant to bending"a rigid strip of metal"
2. incapable of compromise or flexibility
3. incapable of adapting or changing to meet circumstances"a rigid disciplinarian"
4. designating an airship or dirigible having a form maintained by a stiff unyielding frame or structure
5. fixed and unmoving"with eyes set in a fixed glassy stare"