A small exit point in a fortification for the passage of troops when making a sally.
（防御工事的）出击口
Example sentencesExamples
The Sally Port is now no more than a blocked up, arched recess in the foot of the wall. A sally port is a small secure entrance\\exit in a fortified wall. The idea behind this easily defensible doorway is that it can be secured in the event of a siege, and defending troops can easily exit to harry the attackers.
From her tentative perch on the rocks, she could see a sally port in the back of the Citadel, almost completely hidden by the water that had advanced upon it in the hundreds of years now past.
But there was a smaller gate - not quite a sally port, but something similar - in an angle of the wall.
Definition of sally port in US English:
sally port
noun
A small exit point in a fortification for the passage of troops when making a sally.
（防御工事的）出击口
Example sentencesExamples
The Sally Port is now no more than a blocked up, arched recess in the foot of the wall. A sally port is a small secure entrance\\exit in a fortified wall. The idea behind this easily defensible doorway is that it can be secured in the event of a siege, and defending troops can easily exit to harry the attackers.
From her tentative perch on the rocks, she could see a sally port in the back of the Citadel, almost completely hidden by the water that had advanced upon it in the hundreds of years now past.
But there was a smaller gate - not quite a sally port, but something similar - in an angle of the wall.