Court punished Yankee's public protest (6)
I believe the answer is:
outcry
'public protest' is the definition.
(I've seen this in another clue)
'court punished yankee's' is the wordplay.
'punished' indicates anagramming the letters.
'yankee' becomes 'Y' (phonetic alphabet: alpha, bravo, charlie etc.).
'court' with letters rearranged gives 'outcr'.
'outcr'+'y'='OUTCRY'
(Other definitions for outcry that I've seen before include "Widespread protest - clamour" , "Anguished chorus" , "indignation" , "Vociferous protest" , "Sea eagle" .)