Phelloplastic is an uncommon word (to say the least) that means both "a model made of cork" and "the art of making models out of cork".
In the 1700s there was a surge of cork carving in Europe, particularly in Italy. Architects would carve detailed models of famous buildings out of cork, and while we may scoff today, the pieces they created were no laughing matter. Cork is light and easy to carve, although very delicate, and took on the same role balsa wood fills today.
Of course, Europeans weren't going to use such a crude word as "cork" for these works of art. They turned to the Greek language for inspiration, and found phelló, meaning 'cork' and plastikos, meaning 'able to be molded'. (Originally it was actually 'fello-plastic', but the funky non-phonetic spelling won out in the end. That's English for you.)
While cork carving is no longer big in Europe, it is still practiced in China. It is likely that the art moved from Europe to China in the early 1900s, and it has been being carefully developed and refined ever since. Impressive cork carvings are still made in China today, sometimes to be shipped back to the Western world as a 'traditional Chinese art form'.1 (Which, of course, it is).
The word phelloplastic is no longer used -- at all. Its biggest claim to fame is now among weird word collectors, and even they might not take notice of it but for one error. While the Oxford English Dictionary is always the undisputed king of English language dictionaries (of course they have a king!), the Merriam-Webster's New International Dictionary, Second Edition is an indisputably notable tome, being the largest American English dictionary ever compiled. There is a certain class of person who enjoys finding errors in dictionaries, and the bigger the dictionary the better.
Well, it happened that some lazy lexicographer accidentally gave the pronunciation of phelloplastic as 'felopalstik'. (It should have been feloplastik, of course.) What a hubbub this started! This has earned phelloplastic an undying place in lists of errors that famous dictionaries have made.
And now you know.
1. If there is even a hint of doubt in your mind that cork carving might not be all that I make it out to be, then you must go to http://www.pbase.com/lowthian/image/74592445