The antonyms for the word "unstuff" can be "fill," "stuff," "pack," or "load." These words are used when we need to put something into a container or space. For example, while packing for a trip, we fill our bags with clothes, shoes, and other necessary items. When moving to a new home, we stuff our belongings into cardboard boxes. In contrast, when we unstuff something, we remove items or belongings from a container or a space. Unstuffing is often used when decluttering, organizing, or cleaning out a storage area. Overall, these antonyms represent two very different actions: one involves filling and packing, while the other involves removing and decluttering.