embolus
Em"bo*lus, n.; pl. Emboli. Etym: [L., fr. Gr. Emblem.] 1. Something inserted, as a wedge; the piston or sucker of a pump or syringe. 2. (Med.) Defn: A plug of some substance lodged in a blood vessel, being brought thither by the blood current. It consists most frequently of a clot of fibrin, a detached shred of a morbid growth, a globule of fat, or a microscopic organism.