'antiproteinase' is a modern formed word combining the prefix 'anti-' (from Greek anti- meaning 'against') with 'proteinase' (protein + the enzyme-forming suffix '-ase').

'protein' comes from Greek 'proteios' meaning 'primary' or 'of first importance'; the enzyme suffix '-ase' was coined in the late 19th century to name enzymes (e.g., 'proteinase' = an enzyme that acts on protein). The compound 'antiproteinase' was later formed in scientific usage to denote an agent acting against proteinases.

Initially formed to mean 'against proteinases' in a literal biochemical sense; it has remained a technical term meaning an inhibitor of protein-degrading enzymes.