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).
Phrases and idioms:
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.
Etymology: OE plume f. med.L pruna f. L prunum
Useful english dictionary. 2012.