Why does a tomato taste like a vegetable if it is a fruit? Tomatoes, along with peppers, squash, eggplant and many other vegetables are fruits. the definition of a vegetable is: Any plant of which the flowers, roots, tubers, leaves â¦ or stems are used as food.In common lexicon, tomatoes are considered vegetables, but botanically, fruits are a separate class.omatoes, along with peppers, squash, eggplant and many other vegetables are fruits. the definition of a vegetable is: Any plant of which the flowers, roots, tubers, leaves â¦ or stems are used as food. In common lexicon, tomatoes are considered vegetables, but botanically, fruits are a separate class.