Unprofessional air pretty much encapsulates colleague (7)
I believe the answer is:
amateur
'unprofessional' is the definition.
(synonyms)
'air pretty much encapsulates colleague' is the wordplay.
I cannot quite understand how this works, but
'colleague' could be 'mate' (I've seen this in another clue) and 'mate' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for amateur that I've seen before include "Receiving no money" , "Layperson" , "Unpaid performer" , "Non-pro" , "Unpaid (sportsman}" .)