What is the meaning of relaxation?

noun

• Physiology) the gradual lengthening of inactive muscle or muscle fibers. (
• Physics) the exponential return of a system to equilibrium after a disturbance.
  • synonyms: relaxation behavior
• A feeling of refreshing tranquility and an absence of tension or worry.
  • usage: "the easiness we feel when sleeping"
  • synonyms: easiness
• An occurrence of control or strength weakening.
  • usage: "the relaxation of requirements"; "the loosening of his grip"; "the slackening of the wind"
  • synonyms: loosening, slackening
• Freedom from activity (work or strain or responsibility. )
  • usage: "took his repose by the swimming pool"
  • synonyms: rest, ease, repose
• A method of solving simultaneous equations by guessing a solution and then reducing the errors that result by successive approximations until all the errors are less than some specified amount.
  • synonyms: relaxation method
• The act of making less strict.
  • synonyms: liberalization, liberalisation