1. to emerge or issue from a narrow or confined space into a wide, open area
Usage: often used of rivers, streams, or military forces
2. to march out from a defile or narrow passage into open country
Usage: military usage

Examples

• The river debouches into the Atlantic Ocean after flowing through the valley.
• The mountain stream debouches from the canyon into a wide plain.
• The troops debouched from the narrow pass and spread across the battlefield.
• Several tributaries debouch into the main river system.
• The canyon debouches onto a vast desert landscape.
• After marching through the gorge, the army debouched into open terrain.