Learned sly choral composition (9)
I believe the answer is:
scholarly
'learned' is the definition.
(similar in meaning)
'sly choral composition' is the wordplay.
'composition' indicates anagramming the letters (letters arranged or composed in a different order).
'sly'+'choral'='slychoral'
'slychoral' with letters rearranged gives 'SCHOLARLY'.
(Other definitions for scholarly that I've seen before include "Learned, academic" , "Erudite" , "in academic style?" , "Involving serious academic study" .)