Close and commonly bald (7)
I believe the answer is:
airless
'close' is the definition.
(I know that close can be written as airless)
I cannot understand how the remainder of the clue works.
(Other definitions for airless that I've seen before include "Lacking ventilation" , "Unventilated" , "Not ventilated" , "Stifling" , "Still" .)