What is the meaning of stiffness?

noun

• The physical property of being inflexible and hard to bend.
• The property of moving with pain or difficulty.
  • usage: "he awoke with a painful stiffness in his neck"
• Firm resoluteness in purpose or opinion or action.
  • usage: "a charming host without any touch of stiffness or pomposity"
• The inelegance of someone stiff and unrelaxed (as by embarrassment.
  • synonyms: awkwardness, clumsiness, gracelessness
• Excessive sternness.
  • usage: "severity of character"; "the harshness of his punishment was inhuman"; "the rigors of boot camp"
  • synonyms: severity, severeness, harshness, rigor, rigour, rigorousness, rigourousness, inclemency, hardness