'antichymosin' originates from Greek prefix 'anti-' (ἀντί) meaning 'against' and from Modern Latin/New Latin 'chymosin', itself derived from Greek 'χυμός' (khumós) meaning 'juice' (used for 'chyme' or digestive juice).

'chymosin' entered scientific New Latin from Greek 'χυμός' (khumós) + the enzyme-forming suffix '-in'; the modern English formation 'antichymosin' was created by adding the Greek-derived prefix 'anti-' to 'chymosin'.

Initially the elements literally meant 'against (the) chymosin/juice'; over time the compound came to denote specifically 'an antibody or agent that neutralizes the enzyme chymosin' in biomedical usage.