Source : Webster's Revised Unabridged Dictionary (1913)

Muffler \Muf"fler\, n.
   1. Anything used in muffling; esp., a scarf for protecting
      the head and neck in cold weather; a tippet.

            Fortune is painted blind, with a muffler above her
            eyes.                                 --Shak.

   2. (Mus.) A cushion for terminating or softening a note made
      by a stringed instrument with a keyboard.

   3. A kind of mitten or boxing glove, esp. when stuffed.

   4. One who muffles.

Muffler \Muf"fler\, n. (Mach.)
   Any of various devices to deaden the noise of escaping gases
   or vapors, as a tube filled with obstructions, through which
   the exhaust gases of an internal-combustion engine, as on an
   automobile, are passed (called also {silencer}).

Source : WordNet®

muffler
     n 1: a tubular acoustic device inserted in the exhaust system
          that is designed to reduce noise [syn: {silencer}]
     2: a scarf worn around the neck
     3: a device that decreases the amplitude of electronic,
        mechanical, acoustical, or aerodynamic oscillations [syn:
        {damper}]