What is another word for valid?

Here are some synonyms for "valid," depending on the context:

Formal/Legal:

* Legitimate

* Authentic

* Legal

* Justifiable

* Sound

* Lawful

General:

* Accurate

* Correct

* True

* Right

* Sound

* Reasonable

* Justified

* Well-founded

* Acceptable

Informal:

* Good

* Okay

* Right on

* In order

The best synonym will depend on the specific meaning of "valid" in the context you are using it.