IPA: /kəʊˈæɡjʊləm/
KK: /koʊˈæɡjʊləm/
A thick mass formed when a liquid, especially blood, changes into a solid or semi-solid state.
The doctor explained that a coagulum had formed at the site of the injury to stop the bleeding.
Coagulum → It is derived from the Latin root "coagulare" (meaning to curdle or clot), which is formed from "co-" (meaning together) and "agere" (meaning to drive or act). The term refers to a substance that has been driven together to form a clot or curd.
Think of the process of 'driving together' ('agere') to form a solid mass or clot, which is what coagulum means.
No commonly confused words.