prune1 / proōn/ • n. a plum preserved by drying, having a black, wrinkled appearance. ∎ inf. an unpleasant or disagreeable person: he was a good leader, but a miserable old prune.prune2 • v. [tr.] trim (a tree, shrub, or bush) by cutting away dead or overgrown branches or stems, esp. to increase fruitfulness and growth. ∎ cut away (a branch or stem) in this way: prune back the branches. ∎ reduce the extent of (something) by removing superfluous or unwanted parts: reduction achieved by working harder or pruning costs. ∎ remove (superfluous or unwanted parts) from something: Elliot deliberately pruned away details.DERIVATIVES: prun·er n.