mid-14c., "bodily constitution," from Old French complexion, complession "combination of humors," hence "temperament, character, make-up," from Latin complexionem (nominative complexio) "combination" (in Late Latin, "physical constitution"), from complexus (see complex, adj.). Meaning "appearance of the skin of the face" is first recorded mid-15c. In medieval physiology, the color of the face indicated temperament or health.