The word "unzipping" typically refers to the act of opening or undoing a zipper. However, there are many synonyms that can be used in its place such as unfastening, opening, undoing, untying and untangling. Additionally, the word "unzipping" can also be replaced by more specific words depending on the context, such as unlocking, unbuttoning or unclasping. These synonyms can help to add variety and richness to your writing, as well as make your meaning clearer to your audience. Just be sure to choose the synonym that best fits the context and intended meaning.