Having to do with the bronchi, which are the larger air passages of the lungs, including those that lead from the trachea (windpipe) to the lungs and those within the lungs. Found on http://www.cancer.gov/dictionary?expand=B
Bron'chi·al adjective [ Confer French bronchial . See Bronchia .] (Anat.) Belonging to the bronchi and their ramifications in the lungs. Bronchial arteries , branches of the descending aorta, accompanying the bronchia in all their ramifications. -- Bronchial ... Found on http://www.encyclo.co.uk/webster/B/103
An herb or substance that relaxes constricting spasms and opens the bronchi or upper part of the lungs, thus improving respiration. Found on http://www.motherherbs.com/herb-glossary.html