Many a complicated issue means waste (6)
I believe the answer is:
misuse
'waste' is the definition.
The definition and answer can be both acts as well as being singular nouns.
Perhaps you can see a link between them that I can't see?
'many a complicated issue' is the wordplay.
'many' becomes 'm' (Roman numeral for a thousand).
'a complicated' indicates anagramming the letters (a complex or confusing ordering of the letters).
'issue' with letters rearranged gives 'isuse'.
'm'+'isuse'='MISUSE'
'means' acts as a link.
Can you help me to learn more?
(Other definitions for misuse that I've seen before include "Treat badly, unfairly" , "Employ or apply wrongly" , "bad treatment" , "Wrongful employment" , "exploitation" .)