The Collaborative International Dictionary
Hygrology \Hy*grol"o*gy\, n. [Gr. ? wet + -logy: cf. F. hygrologie.] (Med.) The science which treats of the fluids of the body.
Douglas Harper's Etymology Dictionary
1790; see hygro- + -ology.
Wiktionary
n. (context medicine English) The science that deals with the fluids of the body.
Wikipedia
Hygrology (from Greek ὑγρός hygro, wet 'and -logy, teaching', derived from λόγος lógos) is the study of water present in small quantities, in liquid or gaseous state. It is significant here that the quantity is not sufficient to be recognized by the viewer as a liquid, but sensorially noticeable or measurable, e.g. is present in the air. One speaks of moisture. is observed that water can wet or penetrate materials in small quantities or may be located in a gaseous state in gases, substances and mixtures.