Enantiostasis is the ability of an open system, especially a living organism, to maintain and conserve its metabolic and physiological functions in response to variations in an unstable environment. The Australian NSW Board of Studies defines the term in its Biology syllabus as "the maintenance of metabolic and physiological functions in response to variations in the environment".
Enantiostasis is not a form of classical homeostasis, meaning "standing at a similar level," which focused on maintenance of internal body conditions such as pH, oxygen levels, and ion concentrations. Rather than maintaining homeostatic (stable ideal) conditions, enantiostasis involves maintaining only functionality in spite of external fluctuations. However, it can be considered a type of homeostasis in a broader context because functions are kept relatively consistent.