To overpack means to pack or fill something beyond its intended or recommended capacity, often resulting in excessive weight or overcrowding. This can refer to physical objects, such as luggage or containers, as well as abstract concepts, such as schedules or tasks. Overpacking can lead to difficulties in transportation, storage, or completion of the task at hand. It can also indicate a tendency to be overly prepared or cautious, sometimes to the point of excess. In short, overpacking is the act of going beyond what is necessary or reasonable in terms of packing or planning.