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1.
Blowing a raspberry or strawberry or making a Bronx cheer is to make a noise signifying derision, real or feigned. It is made by placing the tongue between the lips and blowing, making a sound redolent of flatulence. In the terminology of phonetics, this sound can be described as an unvoiced linguolabial trill . It is never used in human language phonemically (i.e., to be used as a building block of words), but it is widely used across human cultures.

Nomenclature varies: in the United States, Bronx cheer is sometimes used; otherwise, there and in other English-speaking countries, it is known as a raspberry, rasp or razz – the origin of which is an instance of rhyming slang, in which the non-rhyming part of a rhyming phrase is used as a synonym. In this case, "raspberry tart" rhymes with "fart". It was first recorded in 1890.

A Raspberry Pattern or The Raspberry Pattern represents the form that the mouth takes as it produces a noise similar to that created by flatulence, similar to that of gas as it is passed through the rectum.

The term "Bronx cheer" is used sarcastically because it is not a cheer; it is used to show disapproval. The term originated as a reference to the sound used by some spectators in Yankee Stadium, located in the Bronx, New York City.
Dan: Did Lisa flatulate?
Alex: No, it was Ruth, she was blowing a raspberry
by HermioneHands January 12, 2012