noun

1. the science of health and its maintenance; system of principles for the preservation of health and prevention of disease
2. sanitary practices; cleanliness personal hygiene

Etymology: Fr hygiène < Gr hygieinē (technē), (art) of health < hygiēs, healthy, sound < IE *su-gwiyēs, living well < base *su-, well ( > Sans su-, well) + base *gwei-, to live > Gr bios, life, L vivus, living