Humor and Humors

Humour (British English) or humor (American English) is the tendency of experiences to provoke laughter and provide amusement. But this funny version of the word comes from what was once a very serious term in ancient medicine.

The ancient Greeks taught that the balance of four fluids/humours in the human body controlled human health and emotion.

In Latin, humor meant a "body fluid."

The blood was believed to be produced exclusively by the liver.

BILE = a bitter, alkaline, brownish-yellow or greenish-yellow fluid that is secreted by the liver, stored in the gallbladder, and discharged into the duodenum and aids in the emulsification, digestion, and absorption of fats - from Latin bilis "fluid secreted by the liver" (also known as choler),

Excess of yellow bile was thought to produce aggression, and reciprocally excess anger to cause liver derangement and imbalances in the humors.

The Middle English melancholie comes from the Late Latin melancholia and earlier from Greek melancholía meaning the condition of having black bile. An excess of black bile was understood to cause depression, and inversely a decline of feeling or opinion cause the liver to produce blood contaminated with black bile.

Phlegm was thought to be associated with apathetic behavior, as preserved in the word "phlegmatic." In Middle English it was fleem  and in Middle French flemme both from Late Latin phlegma via Greek phlégma meaning "flame" equivalent to phlég(ein) to burn + -ma.