hemothorax n 1: accumulation of blood in the pleural cavity (the space between the lungs and the walls of the chest) [syn: {hemothorax}, {haemothorax}]
Hemothorax \Hem`o*tho"rax\, n. [NL. See {Hemo-}, and {Thorax}.] (Med.) An effusion of blood into the cavity of the pleura. [1913 Webster]