Fruitloopery is not the person — the person is a fruitloop. This word, with -ery on the end, is the crazy stuff itself: wild ideas, wild talk, the habit of thinking in a fruitloop way. It is rare, jokey, and a little mocking. You might use it when a story or a theory sounds wild and not reasonable, not when you mean a medical fact. Though actually, some lists treat it as if it named the person; that mixes the two words. This one names the nonsense, not the human.