Got a clue muddled penning a list (9)
I believe the answer is:
catalogue
'list' is the definition.
(catalogue is a kind of list)
'got a clue muddled penning a' is the wordplay.
'muddled' indicates an anagram.
'penning' indicates putting letters inside.
'got'+'a'+'clue'='gotaclue'
'gotaclue' with letters rearranged gives 'ctalogue'.
'ctalogue' going around 'a' is 'CATALOGUE'.
(Other definitions for catalogue that I've seen before include "Record" , "(Ilustrated) list of items" , "Coagulate into kind of directory" , "From which we order" , "Brochure containing a list of goods for sale" .)