Bronx

A sputtering noise made by pressing the tongue and lips together, used to express either real or faux contempt, mockery, or displeasure; a raspberry. Primarily heard in US. The fans collectively gave the opposing team a Bronx cheer when their relief pitcher walked onto the field.

a rude sound you make by holding your tongue between your lips and blowing Cindy turned around and blew a Bronx cheer at the kids who'd been teasing her.

A raucous expression of displeasure. The sarcastic reference is to how spectators at sporting events in New York City's borough of the Bronx—at Yankee Stadium, for a notable example—let players on visiting teams, and umpires too, know what was on their mind. The classic “Bronx cheer” sound was produced by compressing the lips and blowing, which replicated the sound of passing wind. That noise was earlier called a raspberry (or raspberry tart, the British rhyming slang for “fart”), from which the word “razz” came.