The Collaborative International Dictionary
Ectobronchium
Ectobronchium \Ec`to*bron"chi*um\, n.; pl. Ectobronchia. [NL. See Ecto-, and Bronchia.] (Anat.) One of the dorsal branches of the main bronchi in the lungs of birds.
Wiktionary
ectobronchium
n. A dorsal branch of the avian mesobronchium or prolongation