To set free from a debt, contract or promise.
To disable some kind of connection in software, such as a key binding.
To take bindings off.
To free or make available.
To remove or clear a block or obstruction from.
In whist, to throw away a high card so as not to interrupt one's partner's long suit.
To enable communication again, via telephone, instant messaging, etc., with (somebody previously blocked).
The removal of a block or blockage.