General synonyms:
* Gratis
* Unbound
* Unfettered
* Unrestricted
* Independent
* Liberated
* Unencumbered
* Complimentary
Synonyms for "free of charge":
* Complimentary
* Gratis
* Costless
* Without charge
* No cost
Synonyms for "free to do something":
* At liberty
* Allowed
* Permitted
* Entitled
Synonyms for "free from something":
* Clear
* Rid
* Devoid
* Exempt
* Vacant
* Vacated
Other synonyms:
* Unpaid (referring to work or labor)
* Open (referring to space or access)
* Available (referring to resources or opportunities)
* Unoccupied (referring to space or objects)
The best synonym to use depends on the specific situation and the meaning you want to convey.