n. 1 a an oval fleshy fruit, usu. purple or yellow when ripe, with sweet pulp and a flattish pointed stone. b any deciduous tree of the genus Prunus bearing this. 2 a reddish-purple colour. 3 a dried grape or raisin used in cooking. 4 colloq. the best of a collection; something especially prized (often attrib.: a plum job). plum cake a cake containing raisins, currants, etc. plum duff a plain flour pudding with raisins or currants. plum pudding a rich boiled suet pudding with raisins, currants, spices, etc.
[ OE plume f. med.L pruna f. L prunum ]