One thing in return for another, quip or quod (4,3,3)
I believe the answer is:
quid pro quo
'one thing in return' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'another quip or quod' is the wordplay.
'another' indicates an anagram.
'quip'+'or'+'quod'='quiporquod'
'quiporquod' anagrammed gives 'QUID PRO QUO'.
'for' is the link.
Can you help me to learn more?
(Other definitions for quid pro quo that I've seen before include "Tit for tat" , "Reciprocal exchanges" , "Return" , "Something given in exchange" , "Reciprocal exchange (Latin)" .)