POSH: smart, elegant, or fashionable; upper class.
Posh is not so much a subculture. You just are Posh or you're not. You can be born Posh (born high class), but you can also become Posh. Posh speak with the highest grade English accent (Queen's English), are very classy, sophisticated, and own expensive things (we purposely didn't say "rich" because we here at Hella Cliques believe that one can be Posh on a budget). However, in England, where they use the term the most, Posh does mean upper class and upper class connotates wealthy. In the US, posh can be interchanged with luxurious, and a Posh is someone who lives a rich, luxurious life.
Disclaimer: We, as humans, like to define things. On these pages, Hella Cliques, through intense research, has tried to bring you the rawest history of each clique. And your factual input is wanted. DON'T BE A POSER!