Baffle

n.
  1. A defeat by artifice, shifts, and turns; discomfiture.
  2. (Engin.) A lever for operating the throttle valve of a winding engine.
    1. 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.
    2. 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.