A change of air, by the way, can be uplifting (5)
I believe the answer is:
raise
'a change' is the definition.
The answer and definition can be both acts as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'air by the way can be uplifting' is the wordplay.
'by' is a charade indicator (letters next to each other).
'the way' becomes 's' (Compass direction - South).
'can be' is an anagram indicator.
'uplifting' becomes 'e' (I can't explain this - if you can you should believe this answer much more).
'air' put after 's' is 'sair'.
'sair' anagrammed gives 'rais'.
'rais'+'e'='RAISE'
'of' is the link.
Can you help me to learn more?
(Other definitions for raise that I've seen before include "What a poker player might do" , "Make greater" , "Lift - increase" , "Make higher" , "Move higher" .)