Part of licence covers air conditioning (9)
I believe the answer is:
character
'part' is the definition.
('character' can be a synonym of 'part')
'licence covers air conditioning' is the wordplay.
'licence' becomes 'charter' (chartering is a kind of licencing).
'covers' is an insertion indicator.
'air conditioning' becomes 'ac'.
'charter' enclosing 'ac' is 'CHARACTER'.
'of' is the link.
(Other definitions for character that I've seen before include "Someone in play" , "Stamp < letter" , "Role - nature" , "Amusing individual" , "Quality" .)