Part of a phrase that usually goes (after one has stated a very unbelievable story) Oh yeah? Where'd you hear that? the Quibbler? -laughs ensue- This references the newspaper The Quibbler that Xenophilius Lovegood of the Harry Potter series prints on a regular basis, which is usually full of ridiculous sightings of fictional creatures and outlandish stories.
The most common term used in reference to a member of Quibblo.com who logs on and creates quizzes or stories daily, and is excessively enthusiastic about the website.
The user "Ripplefart" has taken over 5000 quizzes, created over 200 quizzes, has over 300 friends, and most importantly, logs on everytime she has the chance to. She considers herself a Quibblonian, and does her best not to associate this with the fact that her social life is going rapidly downhill.
The smaller, lesser-known fifth House of Hogwarts. It is a kind of special-ed House where the wizards with mental handicaps are placed. The House color is chartreuse yellow so that the often wandering students can be found easily. Quidditch is played on the gound with cones and a Nerf ball and the players all wear helmets. The Quibbledorf Trio is Leroy (Harry) who has Tourette's and a stutter, Rain (Hermione) who is mentally handicapped and stares and drools and Sampson (Ron) who has a hunchback and is in love with Rain, constantly wiping her drool.
Can also be used as a way to describe someone doing something stupid.
Trying to push open a door that says "pull"...Quibbledorf