Which term refers to a clot that has traveled through the bloodstream?

The term that refers to a clot that has traveled through the bloodstream is 'embolus.' An embolus originates from a thrombus, which is a clot that forms at the site of a damaged blood vessel. When part of this thrombus breaks off and circulates through the bloodstream, it is known as an embolus. This traveling clot can potentially lodge in smaller blood vessels, causing a blockage, which can lead to serious health issues, such as a stroke or pulmonary embolism.

The other terms have distinct meanings and are not interchangeable with embolus. Plethora refers to an excess of blood or other fluids in the body, while phlegmon describes a type of inflammatory condition, often associated with infection, characterized by diffuse, soft tissue inflammation. Thus, 'embolus' is the precise term used to designate a clot that has moved away from its point of origin through the circulatory system.