Source : Webster's Revised Unabridged Dictionary (1913)

Drupel \Drup"el\, Drupelet \Drupe"let\, n. [Dim. of {Drupe}.]
   (Bot.)
   A small drupe, as one of the pulpy grains of the blackberry.

Source : WordNet®

drupelet
     n : a small part of an aggregate fruit that resembles a drupe