What is the antonym for word forbidden?

The antonym for "forbidden" depends on the context, but here are a few options:

General antonyms:

* Allowed

* Permitted

* Authorized

* Legal

* Acceptable

More specific antonyms:

* Welcome (if referring to a person or thing)

* Encouraged (if referring to an action)

* Open (if referring to a place or opportunity)

* Free (if referring to a constraint)

The best antonym will depend on the specific meaning of "forbidden" in the sentence. For example, "The book was forbidden" could be replaced with "The book was allowed" or "The book was welcome".