Where Did the Expression “Sally Forth” Come From and What Does the Phrase Mean?

Today it implies less danger, but to “sally forth” was originally a military term meaning to suddenly rush forward.

The Latin derivation of sally is salire, meaning “to leap.”

Castles and fortresses had closely guarded openings in the walls designed for mounting a quick counterattack against a siege.

These were called sally ports, from which the defenders would vigorously rush, or sally forth, into battle.

So “sally forth” means to go forward with a new venture.