Source : Webster's Revised Unabridged Dictionary (1913)

Moderate \Mod"er*ate\, v. t. [imp. & p. p. {Moderated}; p. pr. &
   vb. n. {Moderating}.]
   1. To restrain from excess of any kind; to reduce from a
      state of violence, intensity, or excess; to keep within
      bounds; to make temperate; to lessen; to allay; to
      repress; to temper; to qualify; as, to moderate rage,
      action, desires, etc.; to moderate heat or wind.

            By its astringent quality, it moderates the relaxing
            quality of warm water.                --Arbuthnot.

            To moderate stiff minds disposed to strive.
                                                  --Spenser.

   2. To preside over, direct, or regulate, as a public meeting;
      as, to moderate a synod.

Source : WordNet®

moderating
     adj : lessening in intensity or strength [ant: {intensifying}]