First, some words of wisdom:
When you think of the word "fruit", how do you define it? Grows on trees? (Not all of them do.) Tastes sweet? (Some of them are bitter or non-edible.)
The thing is, gastronomy and biology also disagree. What we call a "fruit" or a "vegetable" in the culinary sense is mostly based on tradition, and revolves around their taste and kitchen usability (the same "if it's [...] [tvtropes.org]