In persuasiveness, mad Leo converted queen about college (9)
I believe the answer is:
eloquence
'in persuasiveness' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'mad leo converted queen about college' is the wordplay.
'mad' indicates anagramming the letters.
'converted' indicates anagramming the letters.
'about' is an insertion indicator.
'college' becomes 'c'.
'queen' is an anagram of 'quene'.
'quene' going around 'c' is 'quence'.
'leo' is an anagram of 'elo'.
'elo'+'quence'='ELOQUENCE'
Can you help me to learn more?
(Other definitions for eloquence that I've seen before include "Fluency with words" , "Fluency in language" , "Fluency of expression" , "way with words" , "Powerful and effective language" .)