1560s, "study and description of natural objects, natural philosophy" (a sense now obsolete), from French physiologie (16c.) or directly from Latin physiologia "natural science, study of nature," from Greek physiologia "natural science, inquiry into nature," from physios "nature" (see physio-) + logia "study" (see -logy). Meaning "science of the normal function of living things" is attested from 1610s. Related: Physiologic; physiologist.
The two words [physics/physiology] had once the same wide meaning of natural science or natural philosophy. They have now been narrowed & differentiated, physics retaining only the properties of matter & energy in inorganic nature, & physiology only the normal functions & phenomena of living beings. [Fowler, 1926]
c. 1600, "of or pertaining to natural science" (a sense now obsolete), from physiology + -ical. From 1814 as "of or pertaining to physiology, relating to the functions and properties of living bodies." Related: Physiologically.
early 15c., irritacioun, in physiology, in reference to sores and morbid swelling, from Old French irritacion or directly from Latin irritationem (nominative irritatio) "incitement, stimulus; irritation, wrath, anger," noun of action from past-participle stem of irritare "to excite, provoke" (see irritate). Meaning "impatient or angry excitement" is from 1703.
1878 in the physiology sense of "the sum of the chemical changes within the body by which the protoplasm is renewed, changed, or prepared for excretion," from French métabolisme, from Greek metabole "a change," from metaballein "to change," from meta "change" (see meta-) + ballein "to throw" (from PIE root *gwele- "to throw, reach"). The word also has been used in theology, poetics, and entomology.
