1. Small North American diving duck; males have bushy head plumage
   "The butterball's puffy head feathers gave it a comical appearance";
   - bufflehead, dipper, Bucephala albeola
    
2. [N. Amer, informal] An overweight or obese person
   "The schoolyard bully cruelly called him 'butterball'";
   - fatso [informal], fatty [informal], fat person, roly-poly [informal], blimp [N. Amer, informal]

Derived forms: butterballs

Type of: duck, large person

Part of: Bucephala, genus Bucephala

Encyclopedia: Butterball