Robert PattinsonThe term "Robsessed" hasn't officially made it into the Merriam-Webster Dictionary, but chances are the screaming, fawning hordes of teenage (and sometimes older) girls who like 'Twilight' heartthrob Robert Pattinson more than a friend probably already know its meaning ... because, well, they are Rob-sessed. Loosely defined, Rob-session is "a deeply rooted obsession with Robert Pattinson spawned by his portrayal of goodhearted vampire Edward Cullen in the 'Twilight' movies and fueled by his charming smile, devastating good looks and always perfectly mussed hair."

Not coincidentally, 'Robsessed' is also the name of a new documentary that chronicles this phenomenon, which usually involves massive groups of devotees, all screaming and all intent on having some type of contact -- a photo, a handshake or just a sighting from 100 yards away -- with the actor every time he leaves the house.