Definitions for "SALLY PORT"
A gate (or Postern) through which soldiers could "sally forth" to counterattack. In larger forts may be a tunnel through the walls and earthworks.
n. an access control area with doors or gates secured by interlocks such that only one may be opened at a time
A double gate at a sentry station providing access control to a restricted area. Both "vehicle" and "man" versions were used. Originally used in describing fortifications for castles, towers, etc. meaning "a discreet exit which allows the defenders to 'sally forth' and engage the attackers." More information.