Battery (Gun) = A place where theres a number of Guns (Cannons) that can give heavy fire.
Blockhouse = Small fortified Barrack.
Caponier = A Structure used to defend the botom of the ditch and in some cases used as a covered passageway to connect one side of a ditch to the other.
Casemate = A Bombproof Chamber.
Counterscarp = Opposite side (Enemy side) of a defensive ditch.
Demi-Bastion = Half a Bastion with only one Flank.
Hornwork = An advanced work (Ditch and Rampart) in front of the main line consisting of 2 Demi-Bastions and a Curtain.
Magazine = A Bombproof structure where Explosive materials (particulary powder) are Stored.
Ravelin = A Ravelin was like a Redan but it was used as an advanced work (Ditch and Rampart) oposite a Curtain wall and with its ditches defended from the Bastions behind it.
Redan = A Redan was 2 Ramparts and ditches projecting out from the main line in an arrowhead shape.
Redoubt = A closed work with ditches all the way around it.It was designed to give shelter to troops if the Scarp of the line got breached and where they could continue defending with good views of the surounding works.
Sally Port = A gateway or passageway through a Fortifications Rampart or Wall.
Scarp = The defended side of a Ditch.