A prune is a dried plum, most commonly from the European plum tree. Not all plum species or varieties can be dried into prunes. A prune is the firm-fleshed fruit (plum) of Prunus domestica varieties that have a high soluble solids content, and do not ferment during drying. Use of the term "prune" for fresh plums is obsolete except when applied to varieties of plum grown for drying.

In botany, a drupe is an indehiscent type of fruit in which an outer fleshy part surrounds a single shell of hardened endocarp with a seed (kernel) inside. These fruits usually develop from a single carpel, and mostly from flowers with superior ovaries.