Has the power to cut half of drab tale (4)
I believe the answer is:
able
'has the power' is the definition.
I can't judge whether this defines the answer.
'cut half of drab tale' is the wordplay.
'cut half of' indicates taking half.
'tale' becomes 'le' (I can't explain this - if you can you should give a lot more credence to this answer).
'drab' with half the letters taken is 'ab'.
'ab'+'le'='ABLE'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for able that I've seen before include "Talented" , "Practised" , "displaying skill" , "Having considerable skill" , "Adept" .)