Health, according to the World Health Organization, is "a state of complete physical, mental and social well-being and not merely the absence of disease and infirmity".
Desirable level of functional or metabolic efficiency of a living being
A state of dynamic equilibrium between an organism and its environment in which all functions of mind and body are normal.
The avoidance of disease and injury and the promotion of normalcy through efficient use of the environment, a properly functioning society, and an inner sense of well-being.
A state of well-being or balance, often physical but sometimes also mental and social; the overall level of function of an organism from the cellular (micro) level to the social (macro) level.