1. a fish-eating duck with a narrow serrated bill and a crested head

Examples

• The red-breasted merganser dove underwater to catch a fish.
• We spotted a hooded merganser swimming near the reeds.
• The merganser’s serrated bill helps it grip slippery fish.
• A pair of mergansers nested by the lake shore.
• The common merganser is larger than other species in its genus.
• Mergansers are excellent divers and swimmers.