Writers know that the adjective "plummy" is somehow associated with the upper classes. It is – it refers to the way an aristo talks as if he had a plum in his mouth. That's a "plummy voice". It has nothing to do with any type of dessert the upper classes may eat.
Many misunderstandings result, and they're getting more and more baroque:
If you want to know, he said, in a puréed-plum voice (he trained at the Central School)... (Adam Mars Jones, London Review of Books, Nov 2012)
The 11the Duke of Marlborough has the garbled, sticky plum-crumble diction of the irredeemably posh. (Sarah Dempster, The Guardian, Nov 17 2012)
Posh TV cook Nigella Lawson’s voice is described as “plummy” but actually it is light and unresonant.
The Guardian even has TV presenter Kirstie Alsopp working for a couple of “plummy magazines” (May 9 2006).
Then there were their lovely families – every member of them worth so much more than the floppy-fringed Oxbridge plums their sons were trying so hard to impress and infiltrate. (Barbara Ellen, The Observer, 12 Aug 2012 Upper-class people are not known as “plums”.)
Full of great stories about the great old guard in the plummy old days of his rich, old town. (Time magazine - they mean "palmy days".)
[The plum] symbolized fertility, abundance, and often featured prominently in religious rituals. Over time, this association with prosperity and wealth led to the name Plum gaining popularity in noble and upper-class families, signifying their privileged status and opulent lifestyle. (ancestry.com. PG Wodehouse was known as "Plum" – his first name was "Pelham".)
You can plume yourself on getting a plum job - it's a bit like preening.
How to Talk Posh I
How to Talk Posh II
How to Talk Posh III
How to Talk Posh IV
How to Talk Posh is now an ebook available here.
