Opus Dei is a term that refers to a Catholic religious organization. However, there are several synonyms that can be used to describe it. One of the terms that can be used is "Work of God." This more general term can be used to describe any work done in service to God or the Church. Another synonym for Opus Dei is "Divine Work." This term emphasizes the divine nature of the work being done, implying that it is not just any work but rather a task assigned by God himself. Other terms that can be used to describe this term include "God's Task" or "God's Mission".