The Collaborative International Dictionary of English v.0.48:

Bronchial \Bron"chi*al\, a. [Cf. F. bronchial. See Bronchia.]
   (Anat.)
   Belonging to the bronchi and their ramifications in the
   lungs.
   [1913 Webster]

   Bronchial arteries, branches of the descending aorta,
      accompanying the bronchia in all their ramifications.

   Bronchial cells, the air cells terminating the bronchia.

   Bronchial glands, glands whose functions are unknown,
      seated along the bronchia.

   Bronchial membrane, the mucous membrane lining the
      bronchia.

   Bronchial tube, the bronchi, or the bronchia.
      [1913 Webster]

WordNet (r) 3.0 (2006):

bronchial tube
    n 1: either of the two main branches of the trachea [syn:
         bronchus, bronchial tube]