The fruit of a plant is the part that houses the seeds. Cucumbers are fruit, as are zuchinni, squashes, eggplant, peppers. Botanically speaking of course-they are the fruit of the plant. Many 'vegetables' are fruits, others are stems (celery comes to mind) seeds, like corn on the cob, and roots like carrots. Then there are the leaves....Science doesn't divide plant foods into groups of 'fruit' or 'vegetable.'