Plumules are small feathers or downy growths on a bird's skin. Synonyms for plumules include fluff, fuzz, down, filaments, tufts, and wisps. Plumules are used to insulate birds from the cold and maintain their body temperature. They are also important for providing buoyancy during flight. Other terms related to plumules include quills, shafts, and barbs. Plumages are the complete set of feathers on a bird, while molting is the process of shedding old feathers and growing new ones. Overall, plumules play a vital role in the survival and adaptation of birds in their respective environments.