debouch
Exit into openness
To debouch is to emerge or issue forth from a narrow or confined space into open ground.
Troops debouch from a mountain pass onto a plain; a river debouches into a bay.
The word is primarily military or geographical: The infantry debouched from the forest into the clearing.
The noun form is debouchment or debouche.
Come out into view
ravine · canyon · defile · gap · narrows · opening · passage · constriction
emerge
Come out into view
gorge · ravine · canyon · defile · gap · narrows · opening · passage · constriction · bottleneck
mouth
Oral opening
confluence · discharge · empty · flow · channel · stream · watercourse · drainage · basin · tributary
emerge
Come out into view
sally · maneuver · flank · column · formation · march · charge · assault · breakthrough · offensive