Here's an explaination of the word POSH

Just finished visited Chooi; he had explained the origin of the word "POSH". It stands for "Port Out Starboard Home". Back in the old days people used boats to travel not jets. So in order to have people waving goodbyes to you, you pay "extra" for the Port side to wave; you are being seen. Then get the starboard side coming home so people can see you coming home - your porter, your maid, whoever else. Of course, you pay "extra" as well. There you go. That's what the word "POSH" means.