While the coconut is a mainstay in the diet of nearly one third of the planet, it's considered exotic in the Western world. Experts describe the coconut as not just a fruit, but a nut and a seed as well – a drupe. It has three layers: the outside layer is known as the exocarp, and the fibrous husk or mesocarp is inside of it. The thin, woody layer surrounding the actual coconut "meat" is the endocarp.