Reason to wind a coil round a small weight (5)
I believe the answer is:
logic
'reason' is the definition.
(logic is using reason)
'wind a coil round a small weight' is the wordplay.
'wind' is an anagram indicator.
'round' indicates putting letters inside.
'a small weight' becomes 'g' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'coil' is an anagram of 'loic'.
'loic' enclosing 'g' is 'LOGIC'.
'to' is the link.
Can you help me to learn more?
(Other definitions for logic that I've seen before include "Reasoned thinking" , "The science of reasoning correctly" , "Dialectics" , "Rational thinking" , "subject with 14 [ARGUMENTS]" .)