humour

the word "humour" entered english in the middle english period, borrowed from the old french "umor" or "humour". this, in turn, derived from the latin "humor", meaning "moisture" or "fluid". the latin term stems from the verb "humere", "to be moist". this physiological origin is key to its semantic evolution. in ancient and medieval medicine, the body was thought to be governed by four cardinal "humours" or fluids (blood, phlegm, yellow bile, black bile), and the balance of these was believed to determine a person's temperament or mood. by the late 16th century, the sense of "mood" extended to "whim, fancy", and then to the modern sense of "quality of being amusing" and "comic writing", influenced by the idea of playful, capricious temperament. thus, the word's journey from a term for bodily fluid to one describing a mental quality encapsulates a profound shift from concrete physiology to abstract psychology and social behaviour.

the word is a simplex loanword from french. it is not productively segmented into smaller, meaningful morphemes in modern english spelling.