A gate in a fortification designed for sorties.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "sally port" in a sentence
"Positioned on the far left flank of the Allied front in the west, it might — if it could be held — become a sally port from which the Allies could thrust into the flank of the German army in France."