buttnmbathon
A painfully long and boaring movie. See: Oliver Stone's Alexander. (better yet don't) Also the name of reviewer Harry Knowles annual film marathon and birthday bash.
Use as an observation: "That movie was one buttnmbathon".
Or mix it up: "That movie was one son-of-a-buttnmbathon"
Or mix it up: "That movie was one son-of-a-buttnmbathon"