Cheerful: shame supercilious (6)
I believe the answer is:
uppity
'supercilious' is the definition.
(thesaurus)
'cheerful shame' is the wordplay.
'cheerful' becomes 'up' (I've seen this in other clues).
'shame' becomes 'pity' (synonyms).
'up'+'pity'='UPPITY'
(Other definitions for uppity that I've seen before include "Impertinent" , "Not easily persuaded" , "attitude" , "Informally presumptuous or arrogant" , "Informally pert or arrogant" .)