What is the origin of the word humour?
The word humour derives from ancient Greek humoral medicine, which posited that a person's capacity to laugh was determined by the balance of four bodily fluids. This medical theory, originating in the fifth century before the common era, linked laughter to the physiological equilibrium of yellow bile, phlegm, blood, and black bile. The term survived the scientific revolution of the seventeenth century when the humours were discarded in favor of modern physiology.