Though many people think of cucumbers as vegetables, the scientific definition indicates that they’re a type of fruit.
This distinction is based primarily on the biological function of the cucumber itself.
In botany (the study of plants), fruits allow a flowering plant to reproduce. A fruit is formed from the ovary that exists within the flower and houses the seeds that will eventually grow into new plants.
Conversely, “vegetable” is a term reserved for other parts of a plant, such as the leaves, stems, or roots (5).
Cucumbers grow from flowers and contain dozens of seeds that may be used to cultivate future generations of cucumber plants. This basic function is what makes them fruits — not vegetables — according to science.