Poet’s lies reinterpreted as a matter of good manners (9)
I believe the answer is:
politesse
'good manners' is the definition.
(politesse is a kind of good manners)
'poet's lies reinterpreted' is the wordplay.
'reinterpreted' indicates anagramming the letters.
'poets'+'lies'='poetslies'
'poetslies' with letters rearranged gives 'POLITESSE'.
'as a matter of' is the link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for politesse that I've seen before include "Etiquette" , "formal courtesy" , "Chivalry" .)