means A soft, sweet stone fruit with smooth skin in shades of purple, red, or gold — or, by extension, something especially desirable, like a 'plum job.'

from From Old English 'plūme,' which traces back through Latin 'prunum' to Greek 'proumnon.' The same root quietly split in two: 'plum' for the fresh fruit, 'prune' for the dried one — siblings from one ancient word. The 'desirable thing' sense came later, picturing the choicest plum picked from the pudding.