There are several but my favourites are morning thunder, and pass wind!
Had gas or passed gas but if you are not that posh and you just want another word one is fluff.
It's a posh way of saying fart
a posh word for the word big is Gargantuan.
Highfalutin
The posh word for sugar is "sucrose."
yes, its a very posh word and nobody but posh people say it anymore.
Soliloquy Resume Pontification
the word doff is not another word for posh. doff means to remove or take off, as clothing.
A Posh Font on MS Word is "French Script MT".
recreation
Lemonard
posh word for when the pollen from one flower reaches another