The Collaborative International Dictionary of English v.0.48:

Abate \A*bate"\ ([.a]*b[=a]t"), v. i. [See Abate, v. t.]
   1. To decrease, or become less in strength or violence; as,
      pain abates, a storm abates.
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            The fury of Glengarry . . . rapidly abated.
                                                  --Macaulay.
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   2. To be defeated, or come to naught; to fall through; to
      fail; as, a writ abates.
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   To abate into a freehold, To abate in lands (Law), to
      enter into a freehold after the death of the last
      possessor, and before the heir takes possession. See
      Abatement, 4.
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   Syn: To subside; decrease; intermit; decline; diminish;
        lessen.

   Usage: To Abate, Subside. These words, as here compared,
          imply a coming down from some previously raised or
          excited state. Abate expresses this in respect to
          degrees, and implies a diminution of force or of
          intensity; as, the storm abates, the cold abates, the
          force of the wind abates; or, the wind abates, a fever
          abates. Subside (to settle down) has reference to a
          previous state of agitation or commotion; as, the
          waves subside after a storm, the wind subsides into a
          calm. When the words are used figuratively, the same
          distinction should be observed. If we conceive of a
          thing as having different degrees of intensity or
          strength, the word to be used is abate. Thus we say, a
          man's anger abates, the ardor of one's love abates,
          "Winter's rage abates". But if the image be that of a
          sinking down into quiet from preceding excitement or
          commotion, the word to be used is subside; as, the
          tumult of the people subsides, the public mind
          subsided into a calm. The same is the case with those
          emotions which are tumultuous in their nature; as, his
          passion subsides, his joy quickly subsided, his grief
          subsided into a pleasing melancholy. Yet if, in such
          cases, we were thinking of the degree of violence of
          the emotion, we might use abate; as, his joy will
          abate in the progress of time; and so in other
          instances.
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