HYDROPATHY
hydropathy, hydrotherapy
(noun) the internal and external use of water in the treatment of disease
Source: WordNet® 3.1
Etymology
Noun
hydropathy (countable and uncountable, plural hydropathies)
The therapeutic use of water, either internally or externally.
Synonym: hydrotherapy
Source: Wiktionary
Hy*drop"a*thy, n. Etym: [Hydro-, 1 + Gr.
Definition: The water cure; a mode of treating diseases by the copious and
frequent use of pure water, both internally and externally.
Source: Webster’s Unabridged Dictionary 1913 Edition