Formal:
* Declare: To state something officially and publicly.
* Proclaim: To announce something loudly and publicly, often with a sense of authority.
* Publish: To make something known to the public, usually in writing.
* Disseminate: To spread information widely.
* Broadcast: To transmit information widely, usually through radio or television.
Informal:
* Say: A general term for communicating something verbally.
* Tell: To inform someone about something.
* Let someone know: To inform someone, often in a casual way.
* Break the news: To share important information, often unexpected.
* Shout: To announce something loudly, often with excitement.
* Whisper: To announce something quietly, often secretly.
Specific:
* Inaugurate: To formally start something, such as an event or a new era.
* Annunciate: To pronounce something clearly and distinctly.
* Herald: To announce the arrival of something important.
* Foretell: To predict something that will happen in the future.
The best synonym for "announce" depends on the specific situation and what you want to emphasize.