1.  fruitcake(n = noun.person) crackpot, crank, nut, nut case, screwball - a whimsically eccentric person;
is a kind of eccentric, eccentric person, flake, geek, oddball

2.  fruitcake(n = noun.food) - a rich cake containing dried fruit and nuts and citrus peel and so on;
is a kind of cake
has particulars: christmas cake, simnel