hygienics
noun
hy·gien·ics ˌhī-ˈjē-niks 
-ˈje-,
also
-jē-ˈe-niks plural in form but singular in construction
: hygiene sense 1
Example Sentences
Recent Examples on the Web By the turn of the century, Victorians were fluent enough in hygienics to prefer more sanitary surfaces in a bathroom, hence the popularity of white tile. 
Kelsey Keith, ELLE Decor, 17 Feb. 2021
Kelsey Keith, ELLE Decor, 17 Feb. 2021 Word History
First Known Use
1855, in the meaning defined above
Medical Definition
hygienics
noun, plural in form but singular in construction
hy·gien·ics -iks
: hygiene sense 1