Synonyms:
* Unbound: Implies a lack of physical restraint.
* Liberated: Focuses on being released from oppression or control.
* Independent: Emphasizes autonomy and self-reliance.
* Gratis: Means something is given without payment.
* Unencumbered: Means not weighed down or restricted.
* Unconstrained: Implies freedom from limitations.
* Unrestricted: Means without limits or boundaries.
Antonyms:
* Bound: Means to be restricted or held captive.
* Captive: Implies being held against one's will.
* Enslaved: Means being subjected to forced labor or servitude.
* Imprisoned: Means being confined to a prison.
* Constrained: Implies being limited or restricted.
* Restricted: Means having limits or boundaries.
* Charged: Means something has a cost.
The best synonym or antonym depends on the specific context in which you're using the word "free."