Subordinate working as detective, talent almost wasted (10)
I believe the answer is:
incidental
'subordinate' is the definition.
(both can mean less important)
'working as detective talent almost wasted' is the wordplay.
I cannot really see how this works, but
'as' could be 'in' (I've seen this in other clues) and 'in' is present 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 incidental that I've seen before include "Not an essential" , "form of music" , "By the way" , "fortuitous" .)