What is another word for begun?

There isn't a single perfect synonym for "begun" because it depends on the context and the nuance you want to convey. Here are some options depending on the situation:

For general use:

* Started: This is the most common synonym and is often interchangeable with "begun."

* Commenced: This is a more formal synonym.

* Initiated: This emphasizes the beginning of a process or action.

* Launched: This suggests a more forceful or ambitious start.

For specific contexts:

* Embarked: This is used for journeys or projects.

* Undertaken: This is used for tasks or challenges.

* Set in motion: This emphasizes the start of something that will continue.

For emphasizing the past:

* Has begun: This emphasizes that the action has already started.

* Has commenced: This emphasizes that the action has started formally.

* Is underway: This emphasizes that the action is ongoing.

The best word to use will depend on the specific situation and the desired tone.