Make civilised opponents become fairer (9)
I believe the answer is:
enlighten
'make' is the definition.
The answer and definition can be both related to thinking as well as being verbs in their base form.
Maybe there's an association between them I don't understand?
'civilised opponents become fairer' is the wordplay.
I cannot quite see how this works, but
'opponents' could be 'en' (I've seen this in other clues) and 'en' is found in the answer.
The remaining letters 'lighten' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for enlighten that I've seen before include "Impart knowledge to" , "Give instruction" , "Edify" , "remove prejudice" , "Instruct" .)