...is engaged in deliberate 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.
Maybe they are linked in a way I don't understand?
'is engaged in deliberate' is the wordplay.
'engaged in' indicates putting letters inside.
'deliberate' becomes 'muse' (I've seen this in another clue).
'is' put into 'muse' is 'MISUSE'.
Can you help me to learn more?
(Other definitions for misuse that I've seen before include "Ill-treat" , "poor employment" , "harm" , "Apply badly or incorrectly" , "Treat the wrong way or for the wrong purpose" .)