Human blood cells (usually just the red blood cells) that have the same antigens WordNet 3.0 & Open English WordNet

A blood type is a classification of blood, based on the presence and absence of antibodies and inherited antigenic substances on the surface of red blood cells. Wikipedia

Classification of blood based on the presence and absence of antibodies. Wikipedia Disambiguation

Classification of blood based on antibodies and antigens on red blood cell surfaces Wikidata

A classification of human blood according to substances on the surface of the erythrocytes OmegaWiki

A blood type. Wiktionary

A classification of blood that is based on the presence or absence of antigens in the red blood cells of an individual. For the purposes of blood transfusion three antigens referred to as "A", "B" and "RhD" (out of a total of 29) are the most important. Based on their presence the human blood can be classified to A, AB, B, and O blood types which are further divided to Rh positive or negative. Wiktionary

Blood classification. Wiktionary (translation)