The word/sound you utter when you want to draw someone's attention to a mistake your friend's made. Also, mocking said friend without saying much. Pretty much always, non-hostile.
The sound uttered by the thrower of any object when it is tossed across the room or playing field and lands successfully in a trash basket, garbage receptacle, or its intended destination. An interjection. An excited exclamation of victory usually accompanied by the triumphant raising of a fist, high five or thumbs up.
The boy uttered "FITCHOON" through the silence of the room, as his wadded up assignments found their mark one afternoon.
A fitchfork is a feminine instrument according to Stupendilicious. Much similar to a pitch fork, but this type of fitchfork holds meat in place for steady carving, slicing and serving.