1. One who derives great pleasure in the failings of the New York Yankees and feels sickened by their successes; (2) the opposite of one who roots for the New York Yankees.
Due to the fact that the New York Yankees have won so many championships, 27 as of this definitions posting, it is more acceptable to call the winner of the World Series that year's Yankeeship.
"Championships, we couldn't even call it that. We've got so many of them we might as well call them Yankeeships." LordKaT