What does RELAXATION mean?

noun

1. (physiology) the gradual lengthening of inactive muscle or muscle fibers
2. (physics) the exponential return of a system to equilibrium after a disturbance
3. a feeling of refreshing tranquility and an absence of tension or worry“the easiness we feel when sleeping”
4. an occurrence of control or strength weakening“the relaxation of requirements”
5. freedom from activity (work or strain or responsibility)“took his repose by the swimming pool”
6. 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
7. the act of making less strict