Hemagglutination is a process where red blood cells clump together when exposed to certain substances, such as viruses or antibodies. Hemagglutination is one way that viruses are able to infect host cells. Synonyms for hemagglutination include hemagglutinate and agglutination. These terms describe the process of agglutinating, or clumping together, of red blood cells. Other synonyms for hemagglutination include erythrocyte agglutination, red cell agglutination, and blood cell clumping. Hemagglutination is an important phenomenon in many biological and medical contexts, and understanding its properties is essential for the development of effective treatments for infectious diseases.