A duck that comes to a pointed conclusion (7)
I believe the answer is:
pintail
'a duck that comes to a pointed conclusion' is the definition.
'pintail' can be an answer for 'a duck' (pintail is a kind of duck). I'm not sure about the rest of the definition.
'a duck that comes to a pointed conclusion' is the wordplay.
I cannot really see how this works, but
'a' is found in the answer.
'to' could be 'til' (I've seen this in another clue) and 'til' is located in the leftover letters.
'conclusion' could be 'pin' (pin is a kind of conclusion) and 'pin' is located in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for pintail that I've seen before include "Species of duck" , "Breed of duck" .)