The phrase "zips up" can be substituted with a variety of synonyms to convey the same or similar meanings. For instance, words like "fastens", "closes", "secures", "shuts", "zippers", "pulls up", and "ties up" can be used interchangeably with "zips up" depending on the context and the type of closure being referred to. These synonyms are particularly handy when writing or speaking about clothing items that need to be closed or fastened, such as jackets, trousers, and bags. Overall, using synonyms for "zips up" adds variety to the language and helps to keep the reader engaged.