1) Haemagglutination 2) Hemoagglutination 
Hemagglutination, or haemagglutination, is a specific form of agglutination that involves red blood cells (RBCs). It has two common uses in the laboratory: blood typing and the quantification of virus dilutions. ==Blood typing== Blood type can be determined by using antibodies that bind to the A or B blood group in a sample of blood. For example, ...
(from the article `pregnancy`) Several immunological reaction tests in common use are based upon the inhibition of hemagglutination (clotting of red cells). A positive test is ...
Synonym for haemagglutination ... <haematology> Agglutination of red blood cells, often used to test for the presence of antibodies directed against red cell surface antigens or carbohydrate binding proteins or viruses in a solution. Requires that the agglutinin has at least two binding sites. ... (18 Nov 1997) ... 
(he″mә-gloo″tĭ-na´shәn) agglutination of erythrocytes.
Agglutination of red blood cells.
Type: Term Pronunciation: hē′mă-glū′ti-nā′shŭn Definitions: 1. The agglutination of red blood cells; may be immune as a result of specific antibody either for red blood cell antigens themselves or other antigens that coat the red blood cells, or may be nonimmune as in hemagglutination caused by viruses or ...
[n] - agglutination of red blood cells
visible clumping of red blood cells that can be caused by some viruses, bacteria, and certain diseases in which antibodies are produced that bind to self-red blood cells