Why is the ninth month called September?
1670s, from French hygiène, ultimately from Greek hygieine techne "the healthful art," from hygies "healthy," literally "living well" (personified as the goddess Hygieia), from PIE *eyu-gwie-es- "having a vigorous life." The Greek adjective was used by Aristotle as a noun meaning "health."
hygiene hy·giene (hī'jēn')
The science that deals with the promotion and preservation of health. Also called hygienics.
The conditions and practices that serve to promote or preserve health, as those followed for personal hygiene.