Company abandons helpful worker (9)
I believe the answer is:
operative
'worker' is the definition.
(thesaurus)
'company abandons helpful' is the wordplay.
I cannot really understand how this works, but
'company' could be 'opera' (opera company is a kind of company) and 'opera' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for operative that I've seen before include "Working (person)" , "Functioning; worker" , "desired effect" , "Worker in manufacturing" , "American detective" .)