'alloantibody' originates from Greek, specifically the word 'allos,' meaning 'other,' and 'antibody,' from the English word 'antibody.'

'alloantibody' was formed by combining the Greek word 'allos' with the English word 'antibody' to describe antibodies reacting to antigens from the same species.

Initially, it meant 'antibody against foreign antigens,' and this meaning has largely remained the same in modern usage.