Answer: Peanuts

Peanuts look like a nut, are meaty and fatty like a nut, and even taste like a nut, but in reality they are not even in the same family as nuts, but a member of the legume family. The peanut is, as far as its lineage papers are concerned, a bean.

Other nuts you’re likely familiar with such as almonds, cashews, pine nuts, walnuts, pistachios, and more all come from trees which, outside of the peculiar naming of the peanut, is the defining characteristic of nuts big and small.