'anticoagulate' originates from Greek and Latin, specifically the Greek prefix 'anti-' and the Latin verb 'coagulare', where 'anti-' meant 'against' and 'coagulare' (from 'coagulum') meant 'a clot'.

'Coagulate' comes from Latin 'coagulare' (from 'coagulum') and passed into English (via Late Latin/Old French influences) as 'coagulate'; 'anticoagulate' was then formed in English by adding the prefix 'anti-' to create a medical term meaning 'against coagulation' (usage established in the 19th–20th century).

Initially the parts literally expressed 'against clotting'; over time the combined term became the technical medical sense 'to prevent blood (or another fluid) from clotting'.