thrombus /throm″bəs/ pl. thrombi [Gk, thrombos, lump] , 1. an aggregation of platelets, fibrin, and red blood cells that attaches to the interior wall of a vein or artery, sometimes occluding the lumen of the vessel. Compare embolus. Kinds include agonal thrombus, hyaline thrombus, laminated thrombus, white thrombus. 2. a blood clot
