In which case its a shootbolt keep, which the shootbolt(s) engage into.
Some double French doors have single keeps for each side, whilst others have a double.
Theres probably one at the top of the door, which is inevitably in better condition to help finding an alternative.
Treat the shoot bolts and mechanism to a clean and drink of oil, as once there's a new keep in place you could end up with it getting jammed if its nearly seized.
In which case its a shootbolt keep, which the shootbolt(s) engage into.
Some double French doors have single keeps for each side, whilst others have a double.
Theres probably one at the top of the door, which is inevitably in better condition to help finding an alternative.
Treat the shoot bolts and mechanism to a clean and drink of oil, as once there's a new keep in place you could end up with it getting jammed if its nearly seized.