Passageway for air (4)
I believe the answer is:
duct
(Other definitions for duct that I've seen before include "Pipe, tube" , "Channel" , "Tube for cables, air, etc" , "Enclosed conduit for fluid" , "Pipe for cables or air" .)
I believe the answer is:
duct
(Other definitions for duct that I've seen before include "Pipe, tube" , "Channel" , "Tube for cables, air, etc" , "Enclosed conduit for fluid" , "Pipe for cables or air" .)