D defs.my
Entry 1 sense Webster, 1913

Hygiene

/hī'jēn/ · Hy·gi·ene · IPA /ˈhaɪˌd͡ʒiːn/
01 n. That department of sanitary science which treats of the preservation of health, esp. of households and communities; a system of principles …
  1. 1.
    That department of sanitary science which treats of the preservation of health, esp. of households and communities; a system of principles or rules designated for the promotion of health.