1. [n]  a flat plate that controls or directs the flow of fluid or energy
2. [v]  be a mystery or bewildering to; "This beats me!"; "Got me--I don't know the answer!"; "a vexing problem"
3. [v]  check the emission of (sound)
4. [v]  hinder or prevent (the efforts, plans, or desires) of; "What ultimately frustrated every challenger was Ruth's amazing September surge"; "foil your opponent"

BAFFLE is a 6 letter word that starts with B.

1. \Baf"fle\ (b[a^]f"f'l), v. t. [imp. & p. p. {Baffled}
   (-f'ld); p. pr. & vb. n. {Baffling} (-fl[i^]ng).] [Cf.
   Lowland Scotch bauchle to treat contemptuously, bauch
   tasteless, abashed, jaded, Icel. b[=a]gr uneasy, poor, or
   b[=a]gr, n., struggle, b[ae]gja to push, treat harshly, OF.
   beffler, beffer, to mock, deceive, dial. G. b["a]ppe mouth,
   beffen to bark, chide.]
   1. To cause to undergo a disgraceful punishment, as a
      recreant knight. [Obs.]
            He by the heels him hung upon a tree, And baffled
            so, that all which passed by The picture of his
            punishment might see.                 --Spenser.
   2. To check by shifts and turns; to elude; to foil.
            The art that baffles time's tyrannic claim.
                                                  --Cowper.
   3. To check by perplexing; to disconcert, frustrate, or
      defeat; to thwart. ``A baffled purpose.'' --De Quincey.
            A suitable scripture ready to repel and baffle them
            all.                                  --South.
            Calculations so difficult as to have baffled, until
            within a . . . recent period, the most enlightened
            nations.                              --Prescott.
            The mere intricacy of a question should not baffle
            us.                                   --Locke.
   {Baffling wind} (Naut.), one that frequently shifts from one
      point to another.
   Syn: To balk; thwart; foil; frustrate; defeat.
   

2. \Baf"fle\, v. i.
   1. To practice deceit. [Obs.] --Barrow.
   2. To struggle against in vain; as, a ship baffles with the
      winds. [R.]
   

3. \Baf"fle\, n.
   A defeat by artifice, shifts, and turns; discomfiture. [R.]
   ``A baffle to philosophy.'' --South.
   

4. \Baf"fle\, n.
   1. (Engin.)
      (a) A deflector, as a plate or wall, so arranged across a
          furnace or boiler flue as to mingle the hot gases and
          deflect them against the substance to be heated.
      (b) A grating or plate across a channel or pipe conveying
          water, gas, or the like, by which the flow is rendered
          more uniform in different parts of the cross section
          of the stream; -- used in measuring the rate of flow,
          as by means of a weir.
   2. (Coal Mining) A lever for operating the throttle valve of
      a winding engine. [Local, U. S.]