No power in profundity – one instead makes conclusion (5)
I believe the answer is:
death
'conclusion' is the definition.
(I know that death is a type of kill)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for death that I've seen before include "The end - after 13 across, the plague" , "Last moment of existence" , "End of life" , "Distribute; wood" , "The grim reaper" .)