The Collaborative International Dictionary of English v.0.48:

Humor \Hu"mor\, n. [OE. humour, OF. humor, umor, F. humeur, L.
   humor, umor, moisture, fluid, fr. humere, umere, to be moist.
   See Humid.] [Written also humour.]
   1. Moisture, especially, the moisture or fluid of animal
      bodies, as the chyle, lymph, etc.; as, the humors of the
      eye, etc.
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   Note: 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.
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   2. (Med.) A vitiated or morbid animal fluid, such as often
      causes an eruption on the skin. "A body full of humors."
      --Sir W. Temple.
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   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.
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            Examine how your humor is inclined,
            And which the ruling passion of your mind.
                                                  --Roscommon.
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            A prince of a pleasant humor.         --Bacon.
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            I like not the humor of lying.        --Shak.
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   4. pl. Changing and uncertain states of mind; caprices;
      freaks; vagaries; whims.
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            Is my friend all perfection, all virtue and
            discretion? Has he not humors to be endured?
                                                  --South.
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   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.
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            For thy sake I admit
            That a Scot may have humor, I'd almost said wit.
                                                  --Goldsmith.
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            A great deal of excellent humor was expended on the
            perplexities of mine host.            --W. Irving.
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   Aqueous humor, Crystalline humor or Crystalline lens,
   Vitreous humor. (Anat.) See Eye.

   Out of humor, dissatisfied; displeased; in an unpleasant
      frame of mind.

   Syn: Wit; satire; pleasantry; temper; disposition; mood;
        frame; whim; fancy; caprice. See Wit.
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