1. a maritime organization responsible for sea rescue, law enforcement, and safety along coastlines
2. a member of such an organization

Examples

• The coastguard rescued three sailors from the sinking boat.
• She joined the coastguard after graduating from maritime academy.
• The coastguard patrol spotted illegal fishing vessels near the shore.
• A coastguard helicopter searched for the missing swimmer.
• The coastguard issued a warning about dangerous weather conditions.
• He worked as a coastguard for twenty years before retiring.
• The coastguard station monitors radio communications from ships in distress.