Close to being bald when leaving hospital (7)
I believe the answer is:
airless
'close' is the definition.
(I know that close can be written as airless)
'bald when leaving hospital' is the wordplay.
'bald' becomes 'hairless' (similar in meaning).
'when leaving' is a deletion indicator.
'hospital' becomes 'H' (abbreviation for hospital on maps).
'hairless' with 'h' taken away is 'AIRLESS'.
'to being' is the link.
(Other definitions for airless that I've seen before include "Very stuffy" , "Close" , "Lacking ventilation" , "Not ventilated" , "not a breath of wind" .)