plum (n.)
Old English plume "plum, plum tree," from an early Germanic borrowing (Middle Dutch prume, Dutch pruim, Old High German pfluma, pfruma, German Pflaume) from Vulgar Latin *pruna, from Latin prunum "plum," from Greek prounon, later form of proumnon, of unknown origin, perhaps from an Asiatic language (Phrygian?). Also see prune (n.). Change of pr- to pl- is peculiar to Germanic. The vowel shortened in early modern English. Meaning "something desirable" is first recorded 1780, probably in reference to the sugar-rich bits of a plum pudding, etc.