1. biting flies found in coastal areas, especially salt marshes
Usage: regional; informal
2. male mallard ducks, which have distinctive green head feathers
Usage: informal

Examples

• The greenheads were particularly bad at the beach this summer.
• We had to use insect repellent because of all the greenheads.
• The salt marsh was swarming with greenheads during our hike.
• Several greenheads were swimming in the pond with their mates.
• The hunter spotted a group of greenheads near the water’s edge.
• Greenheads can deliver painful bites to beachgoers.
• The wildlife photographer captured images of greenheads in flight.