It's also used as a general greeting and a farewell, so you can use Aloha for goodbye as well.
However, there are other specific ways to say goodbye in Hawaiian, depending on the context:
* A hui hou (pronounced ah-wee hoo): This means "until we meet again" and is a more formal goodbye.
* E komo mai (pronounced eh koh-moh my): This means "come in" and is a friendly way to say goodbye to someone who is leaving.
* Mahalo (pronounced mah-hah-loh): This means "thank you" and can also be used as a polite way to say goodbye.
The best choice depends on the situation and your relationship with the person you are saying goodbye to.