The word "un-zipping" typically refers to the act of opening a zipper or unfastening a garment. The antonyms of "un-zipping" would therefore be words that represent the opposite action, such as "zipping up," "fastening," "closing," or "sealing." These words can be used to describe the act of closing a zipper or fastening a garment, like a coat or jacket. In some cases, antonyms of "un-zipping" can also refer to the act of opening or unfastening something in a different context, such as "uncorking" a bottle or "unlocking" a door. Overall, antonyms of "un-zipping" depend on the context in which the word is used.