1610s, from Medieval Latin Hippocraticus, "pertaining to Hippocrates" (c. 460-377 B.C.E.), the famous ancient Greek physician and "father of medicine." Hippocratic Oath is attested from 1747; it is in the spirit of Hippocrates but was not written by him. The Hippocratic face (1713) is the expression immediately before death or in extreme exhaustion, and is so called from his vivid description of it. The name is literally "one superior in horses;" from hippos "horse" (from PIE root *ekwo- "horse") + kratia "rule" (see -cracy).