'anticoagulant' originates from a combination of Greek and Latin: the prefix 'anti-' (Greek 'anti') meaning 'against' and the Latin verb 'coagulare' (from 'coagulum') meaning 'to clot'; the English noun/adjective-forming suffix '-ant' creates an agent.

'coagulate' developed from Latin 'coagulare' (from 'coagulum' meaning 'clot'), passed into Late Latin and through Romance languages into English; the compound 'anticoagulant' was formed in modern medical English by attaching the prefix 'anti-' to 'coagulant' and entered common medical usage in the 19th and 20th centuries.

Initially it meant 'acting against clot formation' and over time this direct sense has remained the core meaning, now specifically applied to drugs and agents that prevent blood coagulation.