The ancient physicians believed that there were four humors (the blood, phlegm, yellow bile or choler, and black bile or melancholy), on the relative proportion of which the temperament and health depended.
3. State of mind, whether habitual or temporary (as formerly supposed to depend on the character or combination of the fluids of the body); disposition; temper; mood; as, good humor; ill humor. Examine how your humor is inclined, And which the ruling passion of your mind. (Roscommon) A prince of a pleasant humor. (Bacon) I like not the humor of lying. (Shak)
5. That quality of the imagination which gives to ideas an incongruous or fantastic turn, and tends to excite laughter or mirth by ludicrous images or representations; a playful fancy; facetiousness. For thy sake i admit That a Scot may have humor, 8b4
id almost said wit. (Goldsmith) A great deal of excellent humor was expended on the perplexities of mine host. (W. Irving) aqueous humor, crystalline humor or lens, vitreous humor.