Source : Webster's Revised Unabridged Dictionary (1913)

Temperament \Tem"per*a*ment\, n. [L. temperamentum a mixing in
   due proportion, proper measure, temperament: cf. F.
   temp['e]rament. See {Temper}, v. t.]
   1. Internal constitution; state with respect to the relative
      proportion of different qualities, or constituent parts.

            The common law . . . has reduced the kingdom to its
            just state and temperament.           --Sir M. Hale.

   2. Due mixture of qualities; a condition brought about by
      mutual compromises or concessions. [Obs.]

            However, I forejudge not any probable expedient, any
            temperament that can be found in things of this
            nature, so disputable on their side.  --Milton.

   3. The act of tempering or modifying; adjustment, as of
      clashing rules, interests, passions, or the like; also,
      the means by which such adjustment is effected.

            Wholesome temperaments of the rashness of popular
            assemblies.                           --Sir J.
                                                  Mackintosh.

   4. Condition with regard to heat or cold; temperature. [Obs.]

            Bodies are denominated ``hot'' and ``cold'' in
            proportion to the present temperament of that part
            of our body to which they are applied. --Locke.

   5. (Mus.) A system of compromises in the tuning of organs,
      pianofortes, and the like, whereby the tones generated
      with the vibrations of a ground tone are mutually modified
      and in part canceled, until their number reduced to the
      actual practicable scale of twelve tones to the octave.
      This scale, although in so far artificial, is yet closely
      suggestive of its origin in nature, and this system of
      tuning, although not mathematically true, yet satisfies
      the ear, while it has the convenience that the same twelve
      fixed tones answer for every key or scale, C[sharp]
      becoming identical with D[flat], and so on.

Source : WordNet®

temperament
     n 1: your usual mood; "he has a happy disposition" [syn: {disposition}]
     2: excessive emotionalism or irritability and excitability
        (especially when displayed openly)
     3: an adjustment of the intervals (as in tuning a keyboard
        instrument) so that the scale can be used to play in
        different keys