"raspberry" < raspberry tart ? : Cockney rhyming slang?

[Dodi Schultz]

Rudy, it's included in Mathews' *Dictionary of Americanisms* (1951) as razz
or razzberry, a sound indicative of disapproval or derision. (NOT listed
under "raspberry.")

M-W II (1934) has it as both raspberry (orig. E. slang) and razz (US).

*The City In Slang* (Allen, 1993) says that raspberry's a synonym for Bronx
cheer, "classically made by expulsing air through flaccid lips to produce a
very vulgar fluttering sound."

No tarts with any of the above.

--DS