*embolus*

n.; pl. Emboli [ L., fr. Gr. &unr_; pointed so as to be put or thrust in, fr. &unr_; to throw, thrust, or put in. See Emblem. ] 1. Something inserted, as a wedge; the piston or sucker of a pump or syringe. [ 1913 Webster ]

2. (Med.) 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. [ 1913 Webster ]