definition of empyema
home / medterms medical dictionary a-z list / empyema definition Medical Definition of Empyema Empyema: Empyema is a condition in which pus and fluid from infected tissue collects in a body cavity. The name comes from the Greek word empyein meaning pus-producing . Empyema is most often used to refer to collections of pus in the space around the lungs (pleural cavity), but sometimes refers to similar collections in the gall bladder or the pelvic cavity. Empyema may have a number of causes but is most frequently a complication of pneumonia.