Term of endearment; sweetheart, darling.

What is the meaning of Sugar Plum Fairy?

So, with a name that refers to anything and everything sweet and wonderful in the world, it makes sense then that the Sugar Plum Fairy is chosen to rule the Land of Sweets while the Prince is away in Tchaikovsky's The Nutcracker.

What does it mean when you call someone a plum?

The term plum is widely used to describe someone who is an idiot, or to use other colloquial terms knob or bell end.