unbolt

To release the bolts of (a door, for example); unlock.

To release or allow to be opened by withdrawing a bolt: as, to unbolt a door.

To withdraw a bolt and thus open that which it confined; hence (rarely), to open; unfold; explain.

To remove a bolt from; to unfasten; to unbar; to open.

To explain or unfold a matter; to make a revelation.

To undo a bolt; to unlock.

undo the bolt of