英语词源字典 - 在线词源网站

endocrine (adj.)[endocrine 词源字典]: "secreting internally," 1914, from endo- + Latinized form of Greek krinein "to separate, distinguish" (see crisis). Denoting glands having an internal secretion.[endocrine etymology, endocrine origin, 英语词源]
inly (adv.): Old English inlice "internally; sincerely;" see in + -ly (2).
internal (adj.): early 15c., from Medieval Latin internalis, from Latin internus "within, inward, internal," figuratively "domestic," expanded from pre-Latin *interos, *interus "on the inside, inward," from PIE *en-ter- (cognates: Old Church Slavonic anter, Sanskrit antar "within, between," Old High German unter "between," and the "down" sense of Old English under); suffixed (comparative) form of *en "in" (see in). Meaning "of or pertaining to the domestic affairs of a country (as in internal revenue) is from 1795. Internal combustion first recorded 1884. Related: Internally.
hydropathy: "The treatment of illness through the use of water, either internally or through external means such as steam baths (not now a part of orthodox medicine)", Mid 19th century: from hydro- 'of water', on the pattern of allopathy and homeopathy.