'antiautolysin' originates from Modern English/Neo-Latin, formed by combining the prefix 'anti-' (from Greek, meaning 'against') and 'autolysin' (from 'autolysis' + '-in', referring to an enzyme).

'autolysis' comes from Greek 'autos' ('self') + 'lysis' ('loosening, dissolution'); the enzyme name 'autolysin' was created in modern scientific usage to denote enzymes causing autolysis, and 'antiautolysin' was later formed by adding the prefix 'anti-'.

Initially the components literally meant 'against self-dissolving (or the enzyme that causes it)'; it evolved to specifically denote 'a substance that inhibits autolysin' in scientific contexts.