A drupe is a simple fleshy fruit (such as a cherry, plum, or peach) that has a thin outer skin (exocarp) surrounding a fleshy mesocarp that surrounds a hard inedible pit (endocarp), which contains the seed. In aggregate fruits (such as raspberries), the individual sections are called drupelets.
James D. Mauseth, University of Texas, Austin (2009). Botany, an Introduction to Plant Biology, Fourth edition. Jones and Bartlet Publishers, Sudbury Massachusetts. "Fruit Types and Seed Dispersal."