bronchiole
Concise Oxford English Dictionary © 2008 Oxford University Press:
bronchiole /ˈbrɒŋkɪəʊl/
▶noun Anatomy any of the minute branches into which a bronchus divides.
– derivatives
bronchiolar adjective.
bronchiolar adjective.
– origin C19: from mod. L. bronchiolus, bronchiolum, diminutives of late L. bronchia, denoting the branches of the main bronchi.
'bronchiole' also found in these Oxford entries:

