Pneumothorax \Pneu`mo*tho"rax\, n. [Gr. ? air + E. thorax.]
(Med.)
A condition in which air or other gas is present in the
cavity of the chest; -- called also {pneumatothorax}.
pneumothorax
n : abnormal presence of air in the pleural cavity resulting in
the collapse of the lung; may be spontaneous (due to
injury to the chest) or induced (as a treatment for
tuberculosis)