Embolus /(?)/

pl. Emboli

1. Something inserted, as a wedge; the piston or sucker of a pump or syringe.
2. 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. (Med.)