Spoken of morality (4)
I believe the answer is:
oral
'spoken' is the definition.
(similar in meaning)
'of morality' is the wordplay.
'of' indicates the answer is hidden within the clue.
'ORAL' is hidden in the letters of 'morality'.
(Other definitions for oral that I've seen before include "Type of examination" , "By word of mouth (4)" , "Like some tradition" , "Mouth-related" , "Exam using speech" .)