Sentence:  [http://books.google.com.au/books?id=76q-ZwEACAAJ&dq=%22trifecta%22%7C%22trifectas%22+-intitle:%22%22+-inauthor:%22%22&hl=en&sa=X&ei=7QWZUIWVC4memQWG0IDICQ&redir_esc=y Consistently Persistent: Living with the Tourette <WSD>Trifecta</WSD>] 
Meaning of the word marked with <WSD> tags:  A set of three related things, often things that cause problems.