1. n. a silly-acting person. (Also a term of address.) You can be such a silly fruitcake sometimes.
2. n. a male homosexual. (Rude and derogatory. An elaboration of fruit.) We went into this bar, but it was filled with fruitcakes, so we left.
3. and fruit loop n. a foolish oaf. (Someone who is as nutty as a fruitcake. Fruit loop is borrowed from the cereal of the same [protected trade] name.) What a fruitcake! Doesn’t even know where his head is at. Out of the way, fruit loop.