For a traditional, written message sent by wire:
* Wire: This is the most direct synonym, emphasizing the method of transmission.
* Telegraph: This is the older term for the technology itself, so it can be used to refer to the message.
* Dispatch: This suggests a formal or urgent message.
* Cablegram: This refers to a telegram sent via submarine cable.
For a modern, digital messaging platform:
* Text message: This is the most common synonym for a digital message.
* Instant message: This emphasizes the quick delivery of the message.
* Chat: This is a more informal term for a conversation carried out online.
Other options:
* Note: This is a general term for any written message, but it lacks the specific connection to telegram's history.
* Message: This is also a general term, but it doesn't suggest the specific form of a telegram.
The best synonym for "telegram" depends on the specific context and the nuance you want to convey.