Muffler/ˈmʌflər/ Definition 1 of 2Pro Tip 1/3Technical Usage Muffler is often used in the automotive and mechanical fields. During the inspection, the mechanic checked the condition of the muffler. Pro Tip 2/3Noise Reduction Muffler specifically refers to noise control in engines. After the muffler was fixed, the motorcycle ran much more quietly. Pro Tip 3/3Car Maintenance Mentioning a muffler usually implies car maintenance or exhaust problems. My neighbor said his next paycheck was going toward a new muffler.