A nugget is one who is peculiar and puzzling. A nugget may do things no one else understands. A nugget is a synonym for weirdo, loser, or freak.
Girl 1: Today this girl in my chemistry class tripped over her backpack and knocked over the display.
Girl 2: haha she's such a nugget.
Jonah: I'm going to egg Mr. Ratners car today
Mclovin: nahh dude... don't be a nugget. You'd get caught.