noun. The tiny tail of a hamster.
Real citation: "The biggest obstacle to successful rat ownership in the classroom will not come from the students. Most students, being refreshingly open-minded, will take one look at a domestic, or "fancy," rat and immediately become rat advocates. Adults, however, tend to take a bit longer to overcome their squeamishness. It's the tail that does it… for some reason, a naked tail gives many people the willies. Of course, I've never been a fan of the hamster's "smurf stub," so it's all in how you look at it."
("Classroom Animals and Pets - Mammals - Rats," http://www.teacherwebshelf.com/classroompets/mammals-rats.htm)
Made-up citation: "Though hamsters tend to be bitey, solitary, finicky, postal-worker-type hellballs, their smurf stubs are adorable in the eyes of many (though the term is considered offensive to Bluish Americans)."