There are many synonyms for the phrase "come unstuck". Some of the most common synonyms include "fall apart", "break down", "fail", "crumble", "disintegrate", "collapse", "break up", "dissolve", "come apart", "disassemble", "separate", "unravel" and "unravel". These synonyms all suggest that something is not going according to plan or is experiencing difficulties. Whether it is a project, a relationship, or a business, when something comes unstuck it can be frustrating and disappointing. However, it is important to remember that every setback is an opportunity to learn and grow, and with persistence and determination, success can still be achieved.