In the Study of Plants, a drupe or stone fruit is a type of Fruits in which an outer fleshy part (made of the exocarp (“outer fruit” or skin) and mesocarp (“middle fruit” or flesh)) surrounds a single shell (the pip, pit, stone or Pyrena) of a hardened endocarp (“inner fruit” or seed coat) with a seed (Kernel) inside.
In Aggregate Fruits, each individual fruit is called a drupelet.