plum (n.) Look up plum at
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.