homeostasis
/ˌhōmēəˈstāsis,ˌhōmēəˈstasəs/
noun: homeostasis; plural noun: homeostases; noun: homoeostasis; plural noun: homoeostases
- the tendency toward a relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes.
Origin

1920s: modern Latin, from Greek homoios ‘like’ + -stasis.
Description
In biology, homeostasis is the state of steady internal, physical, and chemical conditions maintained by living systems. This is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid balance, being kept within certain pre-set limits. Wikipedia