General Antonyms:
* End: This is the most common and direct opposite of "begin."
* Finish: Similar to "end," meaning to complete something.
* Terminate: To bring something to an end.
* Cease: To stop something.
* Conclude: To bring something to a final stage.
More Specific Antonyms:
* Pause: To stop temporarily.
* Halt: To stop abruptly.
* Suspend: To temporarily stop something.
* Postpone: To delay something.
* Abandon: To give up on something completely.
* Discontinue: To stop doing something.
Contextual Antonyms:
* Continue: If you're talking about continuing something that has already begun.
* Resume: If you're talking about starting again after a pause.
* Revive: If you're talking about bringing something back to life after it had stopped.
The best antonym for "begin" will depend on the specific context and the meaning you want to convey.