The word "un-screw" can be substituted with a number of other synonyms to bring variety and interest to your writing. One option is "unscrew", which has a similar meaning and is often used in technical or mechanical contexts. Another alternative is "undo", which can be more versatile and applies to a wider range of situations. Other possible synonyms include "untwist", "unfasten", "unsnap", "unclasp", and "unbolt". Each option has its own unique connotations and can add different layers of meaning to your writing. By exploring different synonyms for "un-screw", you can improve your writing and make it more engaging for your readers.