What is the meaning of rigid?

adjective

• Incapable of or resistant to bending.
  • usage: "a rigid strip of metal"; "a table made of rigid plastic"; "a palace guardsman stiff as a poker"; "stiff hair"; "a stiff neck"
  • synonyms: stiff
• Incapable of compromise or flexibility.
  • synonyms: strict
• Incapable of adapting or changing to meet circumstances.
  • usage: "a rigid disciplinarian"; "an inflexible law"; "an unbending will to dominate"
  • synonyms: inflexible, unbending
• Designating an airship or dirigible having a form maintained by a stiff unyielding frame or structure.
• Fixed and unmoving.
  • usage: "with eyes set in a fixed glassy stare"; "his bearded face already has a set hollow look- Connor Cruise O'Brien; "a face rigid with pain"
  • synonyms: fixed, set