The DICT Development Group

  Rale \R[^a]le\ (r[aum]l), n. [F. r[^a]le. Cf. Rail the bird.]
     (Med.)
     An adventitious sound, usually of morbid origin, accompanying
     the normal respiratory sounds. See Rhonchus.
     [1913 Webster]
  
     Note: Various kinds are distinguished by pathologists;
           differing in intensity, as loud and small; in quality,
           as moist, dry, clicking, whistling, and sonorous; and
           in origin, as tracheal, pulmonary, and pleural.
           [1913 Webster]