Physical Closure:
* Shut
* Locked
* Sealed
* Covered
* Obstructed
* Blocked
* Enclosed
* Constrained
Metaphorical Closure:
* Finished
* Completed
* Concluded
* Ended
* Terminated
* Resolved
* Settled
* Finalized
Emotional Closure:
* Resolved
* Accepted
* Forgiven
* Healed
* Reconciled
Other:
* Secret
* Private
* Confined
* Restricted
* Limited
Please provide more context for a more accurate synonym! For example, if you're talking about a store being closed, "shut" would be a good synonym. But if you're talking about a deal being closed, "finalized" might be a better choice.