Dictionary definition:
FRUIT:The ripened ovary of a flowering plant that contains the seeds, sometimes fused with other parts of the plant. Fruits can be dry or fleshy. Berries, nuts, grains, pods, and drupes are fruits. Fruits that consist of ripened ovaries alone, such as the tomato and pea pod, are called true fruits. Fruits that consist of ripened ovaries and other parts such as the receptacle or bracts, as in the apple, are called accessory fruits or false fruits
Usage To most of us, a fruit is a plant part that is eaten as a dessert or snack because it is sweet, but to a botanist a fruit is a mature ovary of a plant, and as such it may or may not taste sweet. All species of flowering plants produce fruits that contain seeds. A peach, for example, contains a pit that can grow into a new peach tree, while the seeds known as peas can grow into another pea vine. To a botanist, apples, peaches, peppers, tomatoes, pea pods, cucumbers, and winged maple seeds are all fruits. A vegetable is simply part of a plant that is grown primarily for food. Thus, the leaf of spinach, the root of a carrot, the flower of broccoli, and the stalk of celery are all vegetables.