Deadbolts, which are locks that require a key or turning mechanism to operate, have no direct antonyms. However, if we consider the function of deadbolts in securing doors, then antonyms could include the following:
1. Unsecured: The opposite of a locked or secured door is an unsecured one. In this case, the antonym of deadbolts would be no lock or latch of any kind.
2. Unlocked: Another antonym for deadbolts in the context of a secured door would be unlocked. This means that there might be a lock on the door, but it is not engaged.
3. Open: The ultimate opposite of a deadbolt would be an open door. No lock or latch is involved, and the door is free to be opened without any hindrance.