1. Proteins found on the surface of viruses (especially influenza) or red blood cells that bind to and clump together other cells or particles; plural of hemagglutinin.
Usage: technical; medical/biological; plural form

Examples

• The flu vaccine targets specific hemagglutinins on the surface of influenza viruses.
• Different strains of influenza virus have distinct hemagglutinins that determine their infectivity.
• Hemagglutinins are responsible for the virus's ability to attach to host cells.
• Scientists study hemagglutinins to develop more effective antiviral treatments.
• The H1N1 designation refers to the type of hemagglutinin present on that virus strain.