muffler

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A heavy scarf worn around the neck for warmth.
2. n. A device that absorbs noise, especially one used with an internal-combustion engine.

Century Dictionary and Cyclopedia

1. n. A device to deaden or silence the explosive puff of the exhaust of hot gases from an internal-combustion motor such as is used on motor vehicles. The escape of these gases at high temperatures and pressures into the open air is followed by their expansion, with a shock to the displaced air and a noisy report. The muffler compels them to escape slowly and evenly, and by cooling them in the process less change of volume occurs. The simplest type consists of enlargements of the cross-section of the exhaust-pipe, and the discharge through a large number of small orifices. Called silencer in England.

Wiktionary

1. n. US Part of the exhaust pipe of a car that dampens the noise the engine produces.
2. n. A type of scarf.

GNU Webster's 1913

1. n. Anything used in muffling; esp., a scarf for protecting the head and neck in cold weather; a tippet.
2. n. (Mus.) A cushion for terminating or softening a note made by a stringed instrument with a keyboard.
3. n. A kind of mitten or boxing glove, esp. when stuffed.
4. n. One who muffles.
5. 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).

WordNet 3.0

1. n. a scarf worn around the neck
2. n. a device that decreases the amplitude of electronic, mechanical, acoustical, or aerodynamic oscillations
3. n. a tubular acoustic device inserted in the exhaust system that is designed to reduce noise