"Citrullus" is a genus of plants that includes watermelon and several other species of vine-like fruits. The name "Citrullus" comes from the Latin word for watermelon, "citrullus lanatus." Watermelons are the most well-known member of this genus and are popular for their juicy, sweet red or pink flesh, which is high in vitamins A and C and contains a high amount of lycopene. Other species in the Citrullus genus include citron melon (Citrullus lanatus var. citroides) and colocynth (Citrullus colocynthis), also known as bitter apple.

Cucurbitaceae is the scientific name for the gourd family of plants, which includes a variety of vegetables and fruits such as cucumbers, melons, squashes, and pumpkins. These plants are characterized by their trailing or climbing growth habits and their large, fleshy fruits that have hard seeds enclosed in a protective coat. The fruits of these plants are often used as food sources, while other parts of the plant may also have various uses such as medicinal or ornamental purposes.

I'm sorry for any confusion, but "fruit" is not a medical term per se. It is a common term used to describe the part of a plant that develops from the ovary after flowering and contains seeds. However, in a nutritional or dietary context, "fruits" are often referred to as foods that are typically sweet and juicy, and come from plants' flowers. They are rich in fiber, vitamins, and minerals, making them an essential part of a healthy diet. But in a strict medical sense, there isn't a specific definition for "fruit."