1. A gate or sluice at the head of a canal, irrigation channel, or water system that controls the flow of water into it.
Usage: chiefly used in irrigation and water management contexts

Examples

• The farmer opened the headgate to direct water from the river into the irrigation canal.
• Engineers inspected the headgate to ensure it was functioning properly during the dry season.
• The headgate controls how much water enters the main channel of the aqueduct.
• Maintenance of the headgate is critical for managing water distribution across the farmland.