an indehiscent fruit consisting of outer epicarp, fleshy or fibrous mesocarp, and stony endocarp enclosing a single seed, as in the peach, plum, and cherry
There is also a diminutive form, druplet:
a little drupe, as one of the individual pericarps composing the blackberry.
I'll leave it for you to look up pericarp.
Hope you like it.