A sham critic could possibly be appealing (11)
I believe the answer is:
charismatic
'be appealing' is the definition.
(thesaurus)
'a sham critic could possibly' is the wordplay.
'could possibly' indicates an anagram.
'a'+'sham'+'critic'='ashamcritic'
'ashamcritic' anagrammed gives 'CHARISMATIC'.
(Other definitions for charismatic that I've seen before include "having a strong pull" , "Inspirational in personality" , "inspiring devotion" , "Winning" , "Compellingly attractive" .)