muf-fler / mŭf-lər
1. a heavy scarf worn around the neck to keep one warm
Well, never mind, I will do without it,’ cried little Hans, and he took down his great fur coat, and his warm scarlet cap, and tied a muffler round his throat, and started off.
From “The Happy Prince” by Oscar Wilde, 1854 – 1900
2. any of various devices used to reduce noise, often one used in an internal-combustion engine
The muffler helps reduce the amount of noise produced by your engine as well as also controlling the backpressure of the engine, which improves the endurance and performance of your car’s engine.
“The importance of Muffler in a Car and its Maintenance”, www.germanformula.com/the-importance-of-muffler-in-a-car-and-its-maintenance, accessed January 19, 2022
3. something that suppresses sound
When out looking for deer, a muffler on speech is of paramount importance; and knowing all about this, Thad soon relapsed into silence.
“The Boy Scouts in the Maine Woods” by Herbert Carter pseudonym of Henry St. George Rathbone, 1854 – 1938
Perhaps derived from the Middle English verb mufflen/muffelen (veil, cover, hide), which seems related to the the Old French noun mofle/moufle (mitten, glove) and the Mediaeval Latin noun muffa/muffla/muffula of the same meaning, with both probably having a common Gaulish origin.
Thank you to Allen Ward for providing this etymology.