What is "posh!"

"Posh!" is an up tempo song and musical number from the popular 1968 Albert R. Broccoli motion picture, Chitty Chitty Bang Bang. It is written by the songwriting team of Sherman & Sherman. It makes reference to the myth that the word "posh" is an acronym for " Port Out, Starboard Home". In the film it is sung when "Grandpa Potts" (played by Lionel Jeffries) is being carried away in his outhouse. He sees the situation as serendipitous until he finally meets his kidnapper, Baron Bombhurst in Vulgaria.