To blow hot and cold

Blow \Blow\, v. i. [imp. {Blew} (bl[=u]); p. p. {Blown}
   (bl[=o]n); p. pr. & vb. n. {Blowing}.] [OE. blawen, blowen,
   AS. bl[=a]wan to blow, as wind; akin to OHG. pl[=a]jan, G.
   bl[aum]hen, to blow up, swell, L. flare to blow, Gr.
   'ekflai`nein to spout out, and to E. bladder, blast, inflate,
   etc., and perh. blow to bloom.]
   1. To produce a current of air; to move, as air, esp. to move
      rapidly or with power; as, the wind blows.
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            Hark how it rains and blows !         --Walton.
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   2. To send forth a forcible current of air, as from the mouth
      or from a pair of bellows.
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   3. To breathe hard or quick; to pant; to puff.
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            Here is Mistress Page at the door, sweating and
            blowing.                              --Shak.
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   4. To sound on being blown into, as a trumpet.
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            There let the pealing organ blow.     --Milton.
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   5. To spout water, etc., from the blowholes, as a whale.
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   6. To be carried or moved by the wind; as, the dust blows in
      from the street.
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            The grass blows from their graves to thy own. --M.
                                                  Arnold.
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   7. To talk loudly; to boast; to storm. [Colloq.]
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            You blow behind my back, but dare not say anything
            to my face.                           --Bartlett.
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   8. To stop functioning due to a failure in an electrical
      circuit, especially on which breaks the circuit; sometimes
      used with out; -- used of light bulbs, electronic
      components, fuses; as, the dome light in the car blew out.
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   9. To deflate by sudden loss of air; usually used with out;
      -- of inflatable tires.
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   {To blow hot and cold} (a saying derived from a fable of
      [AE]sop's), to favor a thing at one time and treat it
      coldly at another; or to appear both to favor and to
      oppose.

   {To blow off}, to let steam escape through a passage provided
      for the purpose; as, the engine or steamer is blowing off.
      

   {To blow out}.
      (a) To be driven out by the expansive force of a gas or
          vapor; as, a steam cock or valve sometimes blows out.
      (b) To talk violently or abusively. [Low]

   {To blow over}, to pass away without effect; to cease, or be
      dissipated; as, the storm and the clouds have blown over.
      

   {To blow up}, to be torn to pieces and thrown into the air as
      by an explosion of powder or gas or the expansive force of
      steam; to burst; to explode; as, a powder mill or steam
      boiler blows up. "The enemy's magazines blew up."
      --Tatler.
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