The Collaborative International Dictionary of English v.0.48:

Emphysema \Em`phy*se"ma\, n. [NL., from Gr. ? inflation, fr. ?
   to inflate; ? in + ? to blow: cf. F. emphys[`e]me.] (Med.)
   A swelling produced by gas or air diffused in the cellular
   tissue.
   [1913 Webster]

   Emphysema of the lungs, Pulmonary emphysema (Med.), a
      common disease of the lungs in which the air cells are
      distended and their partition walls ruptured by an
      abnormal pressure of the air contained in them.
      [1913 Webster]

WordNet (r) 3.0 (2006):

emphysema
    n 1: an abnormal condition of the lungs marked by decreased
         respiratory function; associated with smoking or chronic
         bronchitis or old age [syn: emphysema, pulmonary
         emphysema]

Moby Thesaurus II by Grady Ward, 1.0:

63 Moby Thesaurus words for "emphysema":
   Asiatic flu, Hong Kong flu, acute bronchitis, adenoiditis,
   aluminosis, amygdalitis, anthracosilicosis, anthracosis,
   asbestosis, asthma, atypical pneumonia, bituminosis, black lung,
   bronchial pneumonia, bronchiectasis, bronchiolitis, bronchitis,
   bronchopneumonia, catarrh, chalicosis, chronic bronchitis, cold,
   collapsed lung, common cold, coniosis, coryza, croup,
   croupous pneumonia, double pneumonia, dry pleurisy, empyema,
   epidemic pleurodynia, fibrinous pneumonia, flu, grippe, hay fever,
   influenza, la grippe, laryngitis, lipoid pneumonia,
   lobar pneumonia, lung cancer, lung fever, pharyngitis, pleurisy,
   pleuritis, pneumococcal pneumonia, pneumoconiosis, pneumonia,
   pneumonic fever, pneumothorax, quinsy, rheum, siderosis, silicosis,
   sore throat, swine flu, the sniffles, the snuffles, tonsilitis,
   virus pneumonia, wet pleurisy, whooping cough