1. Obstruction or occlusion of a blood vessel by an embolus.
2. An embolus.

[Middle English embolisme, insertion of one or more days in a calendar, from Late Latin embolismus, from Greek embolismos, from emballein, to insert. See emblem.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.