There are several synonyms for the phrase "declare openly" that can be used depending on context and the intensity of the statement. Some of these synonyms include proclaim, announce, publicize, reveal, disclose, unveil, and assert. Each of these words carries a slightly different connotation, with "proclaim" and "announce" suggesting a formal declaration, while "publicize" and "reveal" indicate a wider dissemination of information. "Disclose" and "unveil" suggest a more intentional revelation, while "assert" implies a confident and possibly forceful statement. Choosing the appropriate synonym can add nuance and emphasis to your language, making your message more effective.