General:
* Convey: To make known or understandable.
* Express: To put into words or other forms of communication.
* Impart: To make known or share information.
* Transmit: To send or pass on information.
* Disseminate: To spread or distribute information widely.
More formal:
* Articulate: To express clearly and effectively.
* Elucidate: To make clear or explain.
* Conveyance: The act of communicating.
* Interchange: To exchange thoughts or ideas.
Informal:
* Talk: To speak to someone.
* Chat: To talk in a friendly and informal way.
* Speak: To use words to express oneself.
* Tell: To give information or share a story.
Other:
* Signal: To give a sign or indication.
* Interact: To communicate and cooperate.
* Correspond: To communicate by letter.
* Conveyance: The act of communicating.
The best synonym for "communicate" will depend on the specific situation and the type of communication being described.