Or "posh for the sloshed (as in, drunk)"
A specific but relatively recent
English accent that's somewhere inbetween - or a mix of - Estuary English (EE) and
Contemporary received
pronunciation (RP)
A number of American influences, that sounds like a posh accent that's been loosened after a few glasses of wine, giving off a slurred, but still clear twang to it.
Example: instead of always "BeTTer" it would be sometimes be pronounced inbetween "Bedder" and "beller"
Or "beauddiful" instead of constantly pronouncing it as "BeauTiful"