'antistreptococcus' originates from the Greek prefix 'anti-' meaning 'against' combined with New Latin 'Streptococcus' (from Greek 'streptos' 'twisted' + 'kokkos' 'berry'), where the whole term denotes something acting against streptococci.

'Streptococcus' was formed in New Latin in the 19th century from the Greek roots 'streptos' and 'kokkos'; in medical English the prefix 'anti-' was later attached to produce 'antistreptococcus' to name antibodies/sera or agents active against those bacteria.

Initially the elements meant simply 'against' ('anti-') and the organism name ('Streptococcus'); over time the combined form 'antistreptococcus' came to be used specifically for antibodies, sera, or substances that act against streptococcal bacteria.