I can help you with that. "Puh" is no real word, but just something like an interjection used wenn something is uncool in any way. An english equivalent would probably be "argh" or something like that. Literally translated "trocken" means "dry", but in german it is also used for things that are normally considered barren, wordy and yeah boring. You can use that expression to describe Jura studies or books like "War and Piece" by Tolstoi. So the full sentence means "Argh, that sounds damn boring!".