Webster’s Revised Unabridged Dictionary · 1913 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. ‹ Ectoblast Ectocuneriform ›