whistle-tip
n.— «A “whistle-tip” is a device that is applied to, or is a modification of, a motor vehicle’s exhaust pipe for the sole purpose of creating a high-pitched or shrieking noise when the motor vehicle is operated.» —“Exhaust Systems: Whistle-Tip Prohibition” California Department of Motor Vehicles Jan. 1, 2004. (source: Double-Tongued Dictionary)
Further reading
That sputtering noise when someone sticks out their tongue, puts their lips together, and blows is called a raspberry. No one knows the origin of this slang term, although it may have to do with that pileup of consonants colliding in the middle of...
Sean in New York City is curious about the expression the business end, as in the business end of a gun. It’s simply “the end of an object that fulfills its function or purpose,” such as the business end of a shovel, the business...